1+ 1、2+ 1、2+2、3+ 1、3+2、3+3

4+ 1、4+2、4+3、4+4

5+ 1、5+2、5+3、5+4、5+5

1+ 1、 1+2、 1+3、 1+4、 1+5、

2+ 1、2+2、2+3、2+4、2+5、

3+ 1、3+2、3+3、3+4、

Note: When doing addition exercises, such as "3+5", the right hand will give out "3" first, and the process of "+5" is: say "plus 1" in your mouth and extend your little finger; Say "plus 2" in your mouth and stretch out your thumb with four fingers (note that the thumb only represents "1" in the process of pointing out, and the thumb is only regarded as "5" when deciding the number);

Read "plus 3" in your mouth and stretch out your index finger; Read "plus 4" in your mouth and stretch out your middle finger; Say "plus 5" in your mouth and extend your ring finger. At this time, counting began, only the little finger of the right hand did not open, and the result was "8".

Extended data:

"+"is a plus sign, the numbers before and after the plus sign are addends, "=" is an equal sign, and the numbers after the equal sign are sums.

100 (addend)+(plus sign) 300 (addend) = (equal sign) 400 (sum)

Additive commutative law

a+b=b+a

For example: 8+1=1+8 = 9100+2 = 2+100 =102.

associative law of addition

a+b+c=a+(b+c)