Carry addition

Continuous carry addition

Three-digit pen subtraction does not abdicate the number subtraction on the same number, and one is the back when the number is ten.

abdicate

Successive abdication

Solve practical problems in life

Buy electrical appliances (oral addition and subtraction)

Knowledge points:

1, master the method of adding and subtracting integer hundred and integer ten, and can do oral calculation correctly.

2, can use the knowledge to solve practical problems.

Recycle waste batteries (three-digit pen addition)

Knowledge points:

1, master the calculation method of three-digit addition (no carry, carry, continuous carry), and be able to calculate correctly in writing. During the calculation, the same numbers should be aligned.

2. Estimation method can be used to check the correctness of the calculation results.

3, can use the knowledge to solve practical problems.

Small library (three-digit pen subtraction)

Knowledge points:

1, master the calculation method of three-digit subtraction (no abdication, abdication and continuous abdication), and be able to calculate correctly in writing. In the process of calculation, if you subtract the same counting unit, which digit is not enough to be subtracted, you must retreat to the previous 1, and then subtract the number added to the standard.

2. Estimation method can be used to check the correctness of the calculation results.

3, can use the knowledge to solve practical problems.