Solution: Because 0+ 10= 10, 1+9= 10, 2+8= 10, 3+7= 10, 4+6 =/.

Then the formula of 10 is as follows.

10 can be divided into 0 and 10, 10 can be divided into 1 and 9, 10 can be divided into 2 and 8, 10 can be divided into 3 and 7, 10 can be divided into 4 and 6,/kl.

0 and 10 synthesis 10, 1 9 synthesis10,2 and 8 synthesis10,3 and 7 synthesis10,4 and 6 synthesis/kloc-0,5 and 5 synthesis.

Four operations refer to four operations: addition, subtraction, multiplication and division. Four operations are the important content of primary school mathematics and the basis of learning other related knowledge.

Properties of addition operation

From additive commutative law's associative law, it can be concluded that when several addends are added, the positions of addends can be exchanged at will; Or add a few addends first and then add them with other addends, and the sum remains the same.

Subtraction operation property

Subtracting the sum of two numbers from a number is equivalent to subtracting each addend in the sum from this number in turn.

A number minus the difference between two numbers is equal to this number minus the minuend in the difference, and then the subtraction.

Refer to the above content: Baidu Encyclopedia-Four Arithmetic