15 Best Toys for 1-Year-Olds That Will Keep Them Entertained and Engaged

I recommend checking out the Baby Musical Mat Toddler Toy for fun and learning. The SEREED Baby Balance Bike helps with motor skills development. The Fisher-Price Laugh & Learn Smart Stages Piggy Bank introduces numbers. The Montessori Toddler Busy Board promotes sensory play. Interactive Pop up Animal Toys provide entertainment with music and light. ALASOU Animal Car Baby Toys encourage imaginative play. The Kidwill Wooden Hammering Pounding Toy improves hand-eye coordination. The VTech Pop-a-Balls Push & Pop Bulldozer supports motor skills. Remember, factors such as safety, educational value, and design features are important. These toys are just the beginning of a world of engagement and entertainment options for your curious 1-year-old.

Key Takeaways

• Choose interactive toys with lights, music, and pop-up features for cognitive development.
• Prioritize toys that aid in motor skills with balance bikes, pull string toys, and press-and-go cars.
• Opt for educational toys like busy boards and Montessori sets to enhance learning.
• Focus on toys that provide tactile, visual, and auditory stimuli for engagement.
• Look for durable toys with safety features that support developmental skills and offer long-term entertainment.

Baby Toys for 1 Year Old: Baby Musical Mat Toddler Toys Age 1-2 – 2 in 1 Piano Drum Babies Play Mat

For toddlers aged 1-2, the Baby Musical Mat Toddler Toy is an engaging and educational choice that fosters creativity and coordination skills. This 2-in-1 toy features a piano and drum side, providing multifunctional entertainment.

It helps develop musical interest, improve coordination, and promote creativity and exercise. The toy is designed to be safe, portable, touch-sensitive, and interactive, making it suitable for both boys and girls in the 1-3 age range.

With clear music sounds, adjustable volumes, and a compact design, it's an ideal gift for occasions like Christmas, Thanksgiving, and birthdays. Despite some feedback mentioning issues with the keyboard portion not working, overall positive reviews commend the toy's usability, educational value, and entertainment for children.

Best For: Parents looking for a versatile and educational toy to engage their 1-3 year old children in musical and creative play.

Pros:

• Offers multifunctional entertainment with a 2-in-1 design featuring a piano and drum side.
• Helps in developing musical interest, improving coordination skills, fostering creativity, and promoting exercise in babies.
• Safe, portable, touch-sensitive, and interactive design suitable for young boys and girls.

Cons:

• Some feedback mentions issues with the keyboard portion not working.
• Potential challenges with return and replacement processes.
• Limited warranty information provided, requiring further clarification.

SEREED Baby Balance Bike for 1 Year Old Boys Girls

Ideal for 1-year-olds, this SEREED Baby Balance Bike offers a safe and engaging way to develop balance and coordination skills. Designed for children aged 12-24 months, this balance bike features a sturdy aluminum alloy frame, non-slip TPU handle, and a supportive seat, all made from high-quality, baby-safe materials.

The bike's no-pedal design, fully widened closed wheel, 135-degree turning limit, and gravity steering provide a stable and secure riding experience for little ones. Weighing only 1.6kg (3.6 pounds), this lightweight bike is easy for toddlers to handle indoors and outdoors.

With smooth-rolling wheels suitable for various terrains, this balance bike not only helps strengthen leg muscles but also promotes independence and skill development in a fun and adorable way.

Best For: Parents looking to help their 1-year-old develop balance, coordination, and confidence in a safe and engaging way.

Pros:

• Easy assembly in less than 10 minutes
• Durable and well-made construction
• Lightweight design for toddlers to handle easily

Cons:

• No brake feature may require close supervision
• Limited to indoor and outdoor terrains
• May not accommodate older toddlers beyond 24 months

Fisher-Price Laugh & Learn Smart Stages Piggy Bank

The Fisher-Price Laugh & Learn Smart Stages Piggy Bank offers interactive learning and play for toddlers aged 1 year and above, making it a valuable educational toy choice. This engaging toy features 40+ songs, sounds, and learning phrases to keep little ones entertained while introducing valuable skills.

With Smart Stages levels that teach numbers, counting, colors, and even Spanish words, this piggy bank provides a diverse learning experience. The inclusion of 10 colorful coins for put-and-take play enhances fine motor skills and hand-eye coordination.

Parents and therapists praise its durability and educational value, noting its positive impact on color recognition, counting, and language development. The Fisher-Price Laugh & Learn Smart Stages Piggy Bank is a fun and rewarding way for children to explore and learn.

Best For: Parents looking for an interactive and educational toy to help toddlers aged 1 year and above learn numbers, colors, and develop fine motor skills.

Pros:

• Simple and durable design.
• Educational with multiple learning levels.
• Engaging and entertaining for children.

Cons:

• Tends to tip over easily.
• Lacks volume control.
• Some minor inconveniences reported by users.

Montessori Toddler Busy Board, Wooden Sensory Toy for Boys & Girls

Designed with 27 LED lights and 10 switches, this Montessori Toddler Busy Board by RELODICA is perfect for young children between the ages of 1 and 6, providing a hands-on sensory experience that enhances cognition and fine motor skills development.

This educational toy offers an engaging way for toddlers to learn and practice essential skills. The adjustable LED brightness guarantees the child's eyes are protected, making it safe for extended play.

Portable and compact, it's ideal for travel and keeping little ones entertained on the go. With positive feedback from parents and caregivers, this busy board isn't only durable but also encourages exploration and understanding.

Overall, it's a great gift choice that promotes learning and development in a fun and interactive manner.

Best For: Parents looking for a safe and engaging sensory toy to enhance their toddlers' cognitive and fine motor skills development.

Pros:

• Enhances cognition and sensory development
• Adjustable LED brightness for eye protection
• Portable and suitable for travel

Cons:

• Requires 2 AAA batteries (not included)
• Limited age range of 1-6 years
• Small size may be challenging for older children

Interactive Pop up Animal Toys with Music & Light for 1 Year Old Boy Girl

For toddlers aged 1 year, these Interactive Pop up Animal Toys with Music & Light offer engaging educational play opportunities. Designed to enhance fine motor skills, problem-solving, and logical thinking, these toys feature 5 adorable animals and bright-colored buttons that captivate young minds.

With three play modes – Quiet, Learning, and Game with Music & Light – these toys provide a fun and interactive learning experience. Made of non-toxic ABS material, they're safe for little ones to play with.

Additionally, these toys promote early development by encouraging animal and color recognition, improving hand-eye coordination, and sparking an interest in music. Perfect for tummy time and sitting time activities, these Montessori-inspired toys are ideal for 1-year-old boys and girls, offering both educational benefits and exciting playtime.

Best For: Parents looking for an interactive and educational toy to engage their 1-year-old child in fun learning activities.

Pros:

• Enhances fine motor skills and logical thinking.
• Promotes early development through animal and color recognition.
• Encourages family interaction during playtime.

Cons:

• Some users reported issues with functionality and sound choices.
• Limited variety in animal sounds.
• Suggestions for improvements in the range of animal choices.

LeapFrog Learning Friends 100 Words Book, Green

Ideal for toddlers as young as 18 months, the LeapFrog Learning Friends 100 Words Book in Green is a fantastic bilingual learning tool with interactive touch features. This educational book includes categories like pets, animals, food, colors, and activities, engaging children in a variety of topics.

By touching the words on the pages, kids can hear sounds, facts, and songs, enhancing their learning experience. The book offers a bilingual journey in both English and Spanish, making it a valuable resource for language development.

With dimensions of 9.4' width x 9.2' height x 1.9' depth, it's compact and easy to handle for little hands. Powered by 2 AA batteries (included for demo), this book provides a fun and engaging way for toddlers to expand their vocabulary and knowledge.

Best For: Parents looking for an interactive bilingual learning tool to engage toddlers in expanding their vocabulary and knowledge.

Pros:

• Engaging touch features for interactive learning
• Bilingual experience in English and Spanish
• Compact and easy to handle design for young children

Cons:

• Potential issue with battery leakage
• Limited language options available
• Some users may desire more advanced features for older children

Toys for 1 Year Old Boy Birthday Gift – Silicone Pull String Toy for Toddlers 1-3

This Silicone Pull String Toy is an engaging and developmental choice for a 1-year-old boy's birthday gift. With features like multi-sensory play, various pulling challenges, popping bubbles, and a sliding ball for added fun, this toy offers a stimulating play experience. It's designed to help toddlers develop fine motor skills, enhance sensory perception, promote tactile development, strengthen fine and gross motor skills, and improve hand-eye coordination.

The travel-friendly design makes it a perfect companion for on-the-go entertainment, keeping toddlers engaged during travel. With safe materials and thoughtful designs, this toy provides both entertainment and educational value. The positive customer feedback highlights its sensory engagement, hand skill development, and entertainment value, making it a well-rounded choice for young children.

Best For: Parents looking for a travel-friendly and developmentally stimulating toy for their 1-year-old boy.

Pros:

• Multi-sensory play experience
• Helps in developing fine motor skills
• Travel-friendly design for on-the-go entertainment

Cons:

• Concerns about cleaning instructions
• Some feedback on packaging information
• Potential hazards related to tags

Mingkids Montessori Toys for 1 Year Old, Baby Sorter Toy 6 Pcs Multi Sensory Shape

When choosing toys for 1-year-olds, keep in mind the developmental benefits of Mingkids Montessori Toys, designed to engage young children in hands-on learning experiences.

This educational toy allows babies to explore and learn shapes through 6 colorful multi-sensory blocks made of high-quality ABS plastic. With rounded corners for safety, it's suitable for children aged 1 month and up.

Customer feedback emphasizes the toy's educational value, durability, and entertainment, promoting cognitive development and skills like shape recognition and logical reasoning.

Manufacturer information reveals product dimensions of 4.8 x 4.8 x 4.8 inches and an item weight of 6.3 ounces. The toy supports fine motor skills, problem-solving, and creativity, making it a highly recommended gift for toddlers' birthdays or holidays.

Best For: Parents looking for a safe and engaging educational toy to aid in their 1-year-old's cognitive development.

Pros:

• Promotes hands-on exploration and independent learning.
• Enhances fine motor skills and cognitive abilities.
• Encourages shape recognition, logical reasoning, and creativity.

Cons:

• May be too basic for advanced learners.
• Limited in terms of variety and complexity.
• Some children may lose interest quickly due to simplicity.

VTech Pull and Sing Puppy

For toddlers aged 1 year old, the VTech Pull and Sing Puppy offers a fun and interactive way to develop early motor skills and language abilities. This colorful toy introduces numbers, colors, and body parts through its buttons, promoting fine motor skill development.

The pull string activates music and sounds, engaging children in a playful learning experience. With lights and sounds adding to the excitement, the VTech Pull and Sing Puppy encourages young learners to explore cause and effect relationships.

Its interactive nature not only entertains but also aids in the development of walking and movement skills as children grow. Parents appreciate the toy's quality and durability, making it a favorite among families for its educational value and entertainment factor.

Best For: Parents looking for a fun and educational toy to help toddlers develop early motor skills and language abilities.

Pros:

• Interactive way to introduce numbers, colors, and body parts
• Engaging music and sounds activated by pulling the cord
• Encourages exploration of cause and effect relationships

Cons:

• Some users may find the length of the pull string to be a bit short
• Limited age range suitability (6 months – 3 years)
• Requires 2 AAA batteries for operation

Learning Toys for Toddlers, 20Pcs Farm Animals Toys Montessori Games

The 20-piece farm animals toy set designed for toddlers aged 12-18 months is an excellent choice for introducing early learning concepts through interactive play. This Montessori-inspired toy includes 10 farm animals and 10 barns, featuring shapes like cats, dogs, ducks, cows, and rabbits.

It encourages fine motor skills development and supports learning through number and color matching games. Made of safe materials such as vinyl for animals and non-toxic plastic for barns, this set offers educational activities like counting, sorting, matching, and more.

The vibrant colors of the animals add visual appeal, while the sturdy construction guarantees long-lasting fun. Parents appreciate the interactive nature of this toy, teaching colors, animal names, and prepositions while sparking imaginative play in toddlers.

Best For: Parents looking for an engaging and educational toy set to help toddlers aged 12-18 months develop fine motor skills and learn through interactive play.

Pros:

• Encourages fine motor skills development.
• Supports Montessori learning with number and color matching games.
• Durable and made of safe materials for toddlers' use.

Cons:

• Some concerns about hard plastic corners on barns.
• Limited to toddlers aged 12-18 months.
• Limited to 20 pieces in the set.

iPlay, iLearn Press and Go Car Toys for Toddlers

Ideal for 1-year-olds, the iPlay, iLearn Press and Go Car Toys for Toddlers offer a safe and engaging play experience with their durable design and easy-to-use features. These Baby Animal Racing Cars are designed with rounded edges and smooth surfaces, making them suitable for young children.

Made from high-quality ABS materials, these toys contain no small parts, ensuring a worry-free playtime. The Press to Go feature makes it simple and enjoyable for toddlers to operate, without the need for batteries.

With attractive designs featuring bright colors and cute cartoon characters, these toys stimulate curiosity and imagination in little ones. Compact in size, they're perfect for on-the-go entertainment and help develop motor skills while providing a safe and fast-paced play experience for toddlers.

Best For: Parents looking for a safe and engaging toy that helps develop motor skills for their 1-year-old child.

Pros:

• Durable design with rounded edges and smooth surfaces
• Easy-to-use Press to Go feature without requiring batteries
• Stimulating bright colors and cute cartoon character designs

Cons:

• Limited age range suitability (6 months – 3 years)
• Compact size may be too small for some children
• Made in China, potential concerns about product origin

VTech Drop and Go Dump Truck, Yellow

With its interactive buttons and colorful rocks, the VTech Drop and Go Dump Truck in Yellow is a stimulating educational toy suitable for toddlers aged 1 year and above. This toy is designed to help with motor skill development through activities like dropping the rocks into the truck and pushing it along.

The colorful rocks not only engage children but also encourage them to learn about counting. The interactive buttons add an extra element of fun and learning, keeping toddlers entertained for hours.

With a solid build and engaging features, this dump truck provides a great balance of entertainment and education for young children. Additionally, the VTech brand is known for its quality and innovative toys, making this dump truck a reliable choice for parents looking to enrich their child's playtime.

Best For: Parents looking for an engaging and educational toy to aid in their toddler's motor skill development.

Pros:

• Interactive buttons and colorful rocks enhance learning opportunities
• Encourages counting and fine motor skills
• Durable construction ensures long-lasting playtime

Cons:

• May require supervision for younger toddlers to prevent small parts from being misplaced
• Batteries are required for operation
• Some users may find the price point slightly higher compared to other similar toys

ALASOU Animal Car Baby Toys for 1-2 Year Old Boy

For 1-year-olds looking to engage in imaginative play, the ALASOU Animal Car Baby Toys offer a safe and colorful option to stimulate early learning and motor skills development.

These toy cars are made of sturdy non-toxic ABS material with smooth edges, ensuring a safe play experience. Featuring 4 cute animals in bright colors with an appealing design, these cars are great for improving color recognition and practical abilities.

With a press and go mechanism that requires no batteries, children can easily make the cars run with the tail wagging, encouraging interactive play.

This set is a perfect gift for toddlers and babies, being lightweight, long-lasting, and ideal for birthdays or Christmas.

The ALASOU Animal Car Baby Toys provide a fun and educational playtime experience for young children.

Best For: Parents looking for a safe and colorful toy car set to engage 1-2 year old toddlers in imaginative play.

Pros:

• Made of sturdy non-toxic ABS material with smooth edges for safe play.
• Features 4 cute animals in bright colors, stimulating color recognition and practical abilities.
• Encourages interactive play with a press and go mechanism that requires no batteries.

Cons:

• Mixed reviews on the longevity of the toy cars.
• Some concerns raised about durability and functionality.
• Limited information provided on warranty and support options.

Kidwill Wooden Hammering Pounding Toy for 12+ Months Kids

This wooden hammering pounding toy by Kidwill is an engaging and educational choice for toddlers aged 12 months and above. The multifunctional toy set includes a pounding bench, musical xylophone, and number maze puzzle, providing opportunities for learning and play.

Children can develop hand-eye coordination, fine motor skills, audio recognition, and number recognition while having fun. Crafted with high-quality wood and safe, water-based paint, this toy guarantees durability and safety for young children. With positive feedback from customers highlighting the toy's quality, activities, and educational value, it's a well-received option for toddlers.

The Kidwill Wooden Hammering Pounding Toy isn't only entertaining but also offers a range of developmental benefits, making it a valuable addition to any 1-year-old's playtime.

Best For: Parents looking for a multifunctional and educational toy to engage and entertain their 1-year-old toddlers. This toy is perfect for parents who want to provide their little ones with a fun and stimulating play experience. Not only does it encourage fine motor skills and hand-eye coordination, but it also introduces early learning concepts such as colors, shapes, and numbers. And when the little ones are tucked in for the night, parents can have some fun of their own with adult game night ideas to unwind and relax.

Pros:

• Engaging activities promote learning and development.
• High-quality wood construction ensures durability and safety.
• Positive feedback from customers on the toy's quality and educational value.

Cons:

• Some feedback on the xylophone keys' sound quality.
• Limited age range suitability up to 6 years old.
• May be on the heavier side for younger toddlers to handle.

VTech Pop-a-Balls Push & Pop Bulldozer,Yellow

The VTech Pop-a-Balls Push & Pop Bulldozer in Yellow is an interactive toy that encourages motor skill development and learning for toddlers aged 12 months and up. This bulldozer features a push handle that rolls the toy while popping colorful balls into the bucket.

With buttons for learning colors, numbers, phrases, and music, it offers interactive educational play. The motion sensors trigger fun tunes, adding an engaging element to the play experience.

The chunky handle makes it easy for little hands to push, promoting movement and motor skill development. This toy also includes assorted color balls for extended play options.

Parents appreciate its sturdy construction, bright colors, and the educational value it provides, making it a popular choice for toddlers.

Best For: Parents looking for an interactive toy that promotes motor skill development and educational learning for toddlers aged 12 months and up.

Pros:

• Encourages movement and motor skill development
• Interactive learning with colors, numbers, and music
• Sturdy construction and bright, engaging colors

Cons:

• Some may find it slightly heavy for very young toddlers to carry
• The balls may occasionally get stuck in the chimney
• Limited variety in phrases and music

Factors to Consider When Choosing Toys for 1 Year Olds

When selecting toys for 1-year-olds, it's essential to take into account factors like age-appropriateness, safety, educational value, durability, and developmental skill support.

Ensuring that the toy aligns with the child's age and abilities is key to fostering growth and learning. Safety features are paramount, along with choosing toys that can withstand the wear and tear of active play.

Age-Appropriate Toy Selection

Consideration of age-appropriate factors is crucial when selecting toys for 1-year-olds to make sure their safety and development align. Choosing toys specifically designed for this age group guarantees they're safe and suitable for their developmental stage.

Toys that aid in sensory exploration, fine motor skills, and cause-and-effect learning are beneficial for 1-year-olds. These toys help stimulate curiosity, encourage exploration, and promote cognitive development. Opt for toys that are easy to grasp, manipulate, and interact with, as 1-year-olds are still refining their motor skills.

Look for toys with simple yet engaging features to keep the child entertained and engaged in play. By selecting toys that cater to these age-appropriate factors, you can provide a stimulating and safe play environment that supports your child's growth and development effectively.

Safety Considerations for Toys

Age-appropriate toy selection for 1-year-olds is greatly influenced by safety considerations, particularly when it comes to avoiding small parts, sharp edges, and toxic materials in toys. When choosing toys for young children, it's important to prioritize safety features to prevent accidents and establish a secure play environment.

Look for toys that are free of choking hazards, have secure battery compartments, and use non-toxic paint to minimize health risks. Opt for items with durable construction and sturdy designs that can withstand rough play without breaking. Consider toys with rounded edges, smooth surfaces, and non-breakable components to reduce the chances of injuries during playtime.

It's also essential to choose toys that meet safety standards and have passed quality certifications to guarantee child safety. By paying attention to these safety considerations, you can provide 1-year-olds with toys that not only entertain and engage but also prioritize their well-being.

Educational Value Assessment

Exploring toys that emphasize cognitive development and sensory exploration is vital when selecting items for 1-year-olds. Educational toys for this age group play an important role in promoting cognitive skills, fine motor development, and sensory engagement.

When choosing toys, look for ones that encourage learning colors, shapes, numbers, and basic language skills to stimulate early brain development. Interactive toys that engage multiple senses through tactile, visual, and auditory stimuli can enhance a child's understanding of the world around them.

Additionally, toys that promote problem-solving, cause-and-effect relationships, and spatial awareness can help foster critical thinking skills in young children. It's also beneficial to seek toys that grow with the child, offering increasing challenges and learning opportunities as they reach different developmental milestones.

Durability and Longevity

When selecting toys for 1-year-olds, prioritizing durability and longevity is vital to guarantee safe and lasting play experiences. Opt for toys made from durable materials like wood or high-quality plastic that can withstand rough play and stand the test of time. Look for toys with simple designs and sturdy construction to prevent breakage during active play. It's important to choose toys with rounded edges and smooth surfaces to secure your child's safety while they play. Additionally, consider toys that are easy to clean and maintain to extend their lifespan and keep them hygienic for your little one.

Furthermore, selecting toys with versatile play options or adjustable features can allow the toy to grow with your child, providing long-term entertainment and developmental benefits. By focusing on durability, safety, and maintenance, you can guarantee that the toys you choose for your 1-year-old won't only keep them entertained but also support their growth and development effectively.

Developmental Skill Support

Supporting a 1-year-old's developmental skills through appropriate toy selection is vital for their growth and learning. When selecting toys for a 1-year-old, it's important to take into account their developmental stage and choose toys that can help enhance key skills.

Look for toys that support fine motor skills, hand-eye coordination, and cognitive abilities. Opt for toys that encourage sensory exploration by incorporating different textures, colors, and shapes, as this can aid in their sensory development.

Toys that promote problem-solving and logical thinking can help boost cognitive development, while those that foster social skills and emotional growth through interactive play are also beneficial.

Additionally, selecting toys that support physical development, such as ones that encourage movement, balance, and gross motor skills, can contribute to a well-rounded developmental experience for a 1-year-old.

Engagement and Entertainment

To guarantee your 1-year-old's engagement and entertainment with toys, prioritize selecting ones that are vibrant and interactive. Bright colors, fun sounds, and interactive features are key to capturing their attention. Additionally, toys that encourage movement, such as push toys or pull-along toys, are great for their physical development. Games and puzzles that challenge their problem-solving skills can also be perfect gifts for little boys. These types of toys not only entertain them but also aid in their cognitive and motor skill development.

Look for toys that offer different textures, shapes, and activities to stimulate their senses and curiosity. Opt for options that encourage imaginative play and creativity, as these can enhance cognitive development in 1-year-olds.

Additionally, choosing toys that provide opportunities for exploration and discovery will help your child learn and grow while having fun. By focusing on toys that are engaging and entertaining, you can make sure that your 1-year-old remains active, curious, and excited about playtime.

Remember to take into account their preferences and interests when selecting toys to make the experience even more enjoyable for them.

Frequently Asked Questions

Are Batteries Included With the Interactive Pop-Up Animal Toys?

Yes, batteries are included with the interactive pop-up animal toys. They provide long-lasting entertainment for children. I've found that the included batteries last quite a while, making playtime convenient and enjoyable.

How Do I Clean the Montessori Toddler Busy Board?

To clean the Montessori toddler busy board, I wipe it with a damp cloth. For tougher spots, I gently scrub with a mild soap solution. After cleaning, I air dry it thoroughly before letting my child play.

Can the Baby Balance Bike Be Used Indoors?

Yes, the baby balance bike can be used indoors. It provides a safe and fun way for toddlers to develop balance and coordination. Using it inside allows for year-round active play regardless of the weather outside.

Do the Farm Animals Toys Come With a Storage Bag?

Yes, the farm animals toys come with a storage bag. It's convenient for keeping all the pieces together and organized. I find it helpful in preventing pieces from getting lost and makes cleanup easier.

Are There Different Color Options for the Pull String Toy for Toddlers?

Yes, there are multiple color choices available for the pull string toy for toddlers. This feature adds a fun twist to playtime and allows for personalization based on your little one's preferences.

Conclusion

To sum up, selecting the best toys for 1-year-olds is crucial for their development and entertainment. Furthermore, choosing toys that stimulate their fine and gross motor skills, as well as their cognitive abilities, is essential at this stage. Toys that encourage imaginative play and social interaction are also beneficial for their overall development. In addition to traditional toys, fun family card games can also provide 1-year-olds with opportunities for learning and entertainment in a social setting.

From musical mats to balance bikes, interactive toys to sensory boards, there are numerous options to keep your little one engaged and learning.

Consider factors like safety, durability, and educational value when choosing toys for your child.

With the right toys, you can provide hours of fun and stimulation for your 1-year-old while supporting their growth and development.