IQ Reusable cards with a marker. Chinese puzzles. Counting within 20

The set contains cards with math puzzles. The puzzles are examples of addition and subtraction with numbers up to 20. To solve these tricky Chinese tasks, you will need attention, logic, and resourcefulness. Can't find a solution? Take another look at the pictures -- perhaps you missed some detail. Answers are provided for all puzzles.
For children from 6 years old.