TumbleMath has graciously offered this database free through August 31, 2020!
TumbleMath is the most comprehensive collection of math picture books you will find anywhere. All in the amazing TumbleBook format complete with animation and narration.
The books are accompanied by supplementary materials such as lesson plans and quizzes.
Click on Quiz Portal and you will find a Portal containing thousands of quizzes created by math teachers specifically for your state/provincial standards.