Устный счет 3

Oral account simulator for class 3. Account within 1000. Addition and subtraction, multiplication and division. Continuation of classes in notebooks "3000 examples in mathematics." Observed continuity of levels.

- automatic validation of answers
- explanation of errors
- automatic calculation of exercise time
- the ability to select the number of examples in the exercise
- saving results
- sound information about the correct decision or error

Six difficulty levels:
1. Addition and subtraction within 100 (repetition)
2. Addition and subtraction within 1000 (round numbers)
3. Chains for addition and subtraction within 100
4. Multiplication and division within 100
5. Multiplication and division within 1000 (round numbers)
6. Chains on multiplication and division within 100