Children really understand the meaning of addition and subtraction, not knowing the problem, but understanding the relationship between addition and subtraction. For example, six apples can be divided into two and four apples and vice versa. Meanwhile, two and four apples (or four apples and two apples) add up to six apples. That is to say:
1, teach children from the beginning of decomposition and combination. While expressing it in words, you must say it with your mouth. The child who can say it shows that she has really mastered it.
It starts in 2.5 minutes. Let's talk about decomposition 2 first.
Remember to put them together after each separation.
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)
Example: 7+4+1= 7+(4+1) = (7+4)+1=1210-5+2 = (10)