First, the subtraction table

10- 1=9

10-2=8 9- 1=8

10-3=7 9-2=7 8- 1=7

10-4=6 9-3=6 8-2=6 7- 1=6

10-5=5 9-4=5 8-3=5 7-2=5 6- 1=5

10-6=4 9-5=4 8-4=4 7-3=4 6-2=4 5- 1=4

10-7=3 9-6=3 8-5=3 7-4=3 6-3=3 5-2=3 4- 1=3

10-8=2 9-7=2 8-6=2 7-5=2 6-4=2 5-3=2 4-2=2 3- 1=2

10-9= 1 9-8= 1 8-7= 1 7-6= 1 6-5= 1 5-4= 1 4-3= 1 3-2= 1 2- 1= 1

10- 10=0 9-9=0 8-8=0 7-7=0 6-6=0 5-5=0 4-4=0 3-3=0 2-2=0 1- 1=0

Second, the law of subtraction.

1, the first line is 10 minus a few, that is 10 minus1~10; The second line is all 9 minus1~ 9; The third line is 8 minus 1~8.

2. From top to bottom, the two numbers in the latter formula are 1 less than those in the previous formula, and the numbers are equal. Looking from the top left to the bottom right, the former number of the latter formula is reduced by 1, while the latter number is unchanged, and the number is reduced by 1.

Teach children to add and subtract within 10.

1, chat to stimulate children's computing consciousness

In the usual conversation with children, you can stimulate children's thinking by asking and answering questions, so that "digital calculation" can enter children's world.

For example, "Baby, here are three oranges. Do you want more? " "You have eaten 2 pieces of sugar, and I will give you 1 piece. No more! " At the beginning, there is no need to strictly use standard vocabulary to stimulate children's computing consciousness. As long as you can express the meaning of increase or decrease, how to communicate is easy for children to understand?

2. Understand the meaning of "+"and "-"

+means more, means together. When we ask questions to children, we often use "a * * *, always * * *, together". -That means less. Ask children more questions with "What's left, what's not good, how much more or how much less". This is like the understanding of the meaning of numbers in the last article, which requires that the symbol of the number 3 corresponds to three building blocks.

Take giving candy as an example. Hold 1 candy in your right hand and 2 candy in your left hand. Ask your child how many sweets there are in a box now. If a child has basic knowledge of numbers, he will know that there are three. Understanding of building blocks: 2+3=5.

3. Add first and then subtract, simplify first and then make it difficult.

(1) The order of addition and subtraction is addition first, then subtraction. Many mothers are impatient, and teaching addition and subtraction together may confuse children with the concept of addition and subtraction. Subtraction can be relatively difficult to understand.

(2) Addition sequence: proficiency is less than 5, and then addition is less than 10. Addition within 10 is very important. Children must be skilled and can recite addition formulas on the basis of understanding.

(3) Ten. Until then, add those two numbers to 10, remember. When I play with my child, I teach her: notoginseng equals ten, twenty-eight equals ten, and nineteen equals ten.

(4) After learning to add, you can add within 20 minutes.