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

The book proposes chains of examples on the topic "Actions with round numbers." All tasks are divided into topics: “Addition and subtraction of multiple 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 number 0 up to 9 within 500 ”,“ multiplication and division by numbers 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 according to 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 task, 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 with one or more zeros. For example, 90, 100, 450, 1000, etc. Extracting skills in solving examples with multiple of 5 and 10 numbers will reduce calculation time in more complex chains.