Mathematics. All chains of examples for oral and written work. 4th grade

The book suggests chains of examples on the topic "actions with round numbers".
All tasks are divided into topics:" Addition and subtraction of numbers of multiple 5 and 10 within 50 "," Addition and subtraction of round numbers within 500 "," Addition and subtraction with brackets within 500 "," Multiplication and division by a number from 0 to 9 within 500 "," Multiplication and division by a number from 0 to 9 with brackets within 500 "," Addition and subtraction with brackets and without Within 1000 "," Multiplication and division with brackets and without within 1000 "," Actions with any numbers within 1000 ".
For each topic, the tasks are grouped on two of the same options. Inside each option, examples of different levels of complexity are collected. This will allow the student to work out stable fast account skills. Teachers can use options for testing in lessons or optional classes. To complicate the assignment, when performing each option, you can take less time for calculations.
Round numbers are called multiple 10. It is very simple to recognize them: such numbers end in one or more zeros. For example, 90, 100, 450, 1000, etc.
practicing skills in solving examples with a multiple of 5 and 10 will reduce calculation time in more complex chains