6+7 = 13, 10 divided by 2=5 9-8= 1, 3 multiplied by 4= 12.

Addition:1+2; Subtraction: 9-8-4-3; Multiplication: 5 * 7 *13; Department: 12/6

13-6=7

3*4= 12

1+8=9

10/5=2

definition

Addition: the operation of combining two numbers into one number.

Subtraction: when two addends and one of them are known, the operation of finding the other addend.

Multiplication: the operation of finding the product of two numbers.

Division: the operation of finding another factor by knowing the product of two factors and one of them.

Refer to the above content: Baidu Encyclopedia-Four Arithmetic