Add 9 minus 1, add 8 minus 2, add 7 minus 3, add 6 minus 4, add 5 minus 5, add 4 minus 6, add 3 minus 7, add 2 minus 8, and add/kloc-0 minus 9 (note: the number of words decided orally is a single place). Example: 26+38=64 Solution: Add 8 and subtract 2. Who will subtract 2? 26 minus 2 equals 6. Three out of 38 will get four points.

1 and addition are interchangeable, that is, the order is not important.

2. Addition is interrelated, which means that when more than two numbers are added, the order of addition is not important.

3. Repeatedly adding 1 is the same as counting; Adding 0 will not change the result.

4. Addition also follows related operations (such as subtraction and multiplication).

Extended data

Subtraction The operation of subtracting one number from another is called subtraction. Given the sum of two addends and one of them, the operation of finding the other addend is called subtraction. The symbol of subtraction is "-",which is pronounced as negative sign.

Subtraction follows several important patterns.

1 is anti-commutative, that is, changing the order changes the sign of the answer.

2. It is not an associative law, that is, when a subtraction exceeds two numbers, the order of subtraction is very important.

Subtracting 0 will not change a number.