Use decomposition technique, starting from less than 5 and starting from decomposition 2. Remember to put them together after each separation. Remember to add and subtract large numbers within ten, and add and subtract decimals. You can also use ten songs, abdication subtraction and other formulas.

Keep a large number in mind.

For addition and subtraction within ten, large numbers should be recorded, and decimals should be counted up or down, for example, 4+2= 4, and two numbers, 5 and 6, should be counted up, and then the result is 4+2 = 6; 6-3= remember 6, count down to 3, 5, 4, 3, and then get the result 6-3=3.

Collect ten songs

Compiling ten songs is one of the essential formulas for elementary school students' addition and subtraction, which can help them quickly calculate the addition and subtraction within ten. For example: one plus nine, ten little tadpoles; Two plus eight, ten old ducks; Three plus seven, ten old hens; Four plus six, ten golden monkeys; Five plus five, ten big tigers.

Abdication subtraction

The abdication subtraction is one of the necessary formulas for primary school students to do subtraction, which can help primary school students to quickly calculate the subtraction within ten. For example, abdication subtraction should be kept in mind, starting from the unit; Who is not enough to retire, don't forget to add ten to the standard; If the interval is 1, it is best to remember that 0 becomes 10.