There is a list of various problems at the link.
Calculation problems created with random numbers are the main ones.
Fourth grade arithmetic
- More than 100 million units
- Tables and graphs
- Division pen calculation (divide by 1 digit number)
- Shapes and angles
- Decimals and strokes
- Division pen calculation (divide by a two-digit number)
- Approximate number
- Order of calculations, how to use parentheses
- Shapes: vertical and various rectangles
- True fractions, mantissa fractions, and band fractions
- Multiplication and division of decimal numbers