Kids' Math Book Illustration Upgrade

I'm seeking an illustrator to transform existing images for a children's math education book into engaging, child-friendly, cartoonish visuals. This book targets 9 to 12 year olds, so the illustrations need to be relatable and appealing to this age group.

At first, we will pay to mock-up an illustration/design based on a few pages of the book, and based on feedback we've gotten from users. If your design is selected for the next round, we will pay again to illustrate more pages.

Key Requirements:
- Review our user feedback. Address the areas of improvement with your creativity and artist expression.
- Update existing pictures to be child-friendly; modify font, organize/modify text to complement visual aids
- Create cartoonish illustrations featuring human characters; preference is to create characters that represent different backgrounds/ethnicities across the world. The intent is global appeal.
- Illustrate math concepts by depicting characters in a variety of scenarios. For example, playing games like basketball, soccer, dancing, gymnastics, etc. Or performing everyday tasks like cooking, hiking, walking a pet, etc.

Ideal Skills and Experience:
- Previous experience in children's book illustration
- Ability to create engaging visuals that appeal to a specific age group
- Understanding of incorporating educational content into illustrations
- Creativity in depicting a variety of scenarios and activities