The first monthly examination paper of the fourth grade mathematics volume II 1. Fill in the blanks. (15) 1. In the formula without brackets, if there are only addition and subtraction operations or only multiplication and division operations, they should be calculated in the order of (). 2, (90-2 1× 2) ÷ 12, the calculation should be done first (). There are subtraction and multiplication in brackets, so you have to calculate () first. 3. Addition, subtraction, multiplication and division are collectively called (). 4. List the comprehensive formula according to the following formula. (1) 221× 3 = 663 (2) 217+123 = 340208-16 =13340-/kloc-. 7, 350÷75+ 15×8, and () method and () method can be calculated at the same time.