100- 17-38= ? 18+49+28= ? 22+49-22= 2 1-8+39=

66-27+ 19= 38+ 14+ 19= ? 29+27+26= 37-29+ 16=

45+55-22= 100-65=26= ? 100-39-45= ? 24+47-26=

88-66+49= 28+ 19+ 17= ? 56+26-39= 67+27-45=

5 1-22+39= 73-37+38= ? 29+36-29= 30- 13+68=

100-87+48= ? 66-39+47= ? 25- 18+37= 100-55+45=

Elementary arithmetic law:

(1) In the formula with brackets, the inside of brackets is calculated first, and then the outside of brackets is calculated.

② When there are both addition and subtraction and multiplication and division in the formula without brackets, multiply first, then divide, and then add and subtract.

(3) In the formula without brackets, if there is only addition, subtraction or multiplication and division, it should be calculated from left to right.