Addition within 100 (no carry):
It is based on the estimation of addition within 100, so that students can master the calculation method more accurately.
Ability goal:
1, able to understand the algorithm of aligning the same digits and adding them from single digits, and master vertical writing.
2. Master the calculation method of two-digit addition and the rules of pen addition.
Solution:
Number alignment: number to number, number to number, plus sign moves forward. The calculation starts with digits, and the digits are added, so the digits are written on the digits and the digits are written on the digits.
Addition within 100 (carry)
Learning objectives:
Master the column vertical calculation of carry addition and apply decimal addition to solve practical problems.
Dialing method:
(1) Select addition for calculation, and Equation 38+25=63 is calculated vertically with the learned two-digit binary addition column.
⑵ Pay attention to the vertical calculation of columns: number alignment, number to number, number to number, plus sign moving forward. The calculation starts from the unit. When the unit reaches ten, you should enter 1. Don't forget to answer horizontally.
(3) Attention should also be paid to the application questions: don't forget to write the unit for the results, and answer all the calculations.
For example, there are 38 deaf students and 25 mentally retarded students in Starlight Experimental School. How many students are there in the school?
Solution:
There are 63 students in this school.
/kloc-subtraction within 0/00 (abdication)
Learning objectives:
Master the column vertical calculation of carry addition and apply decimal addition to solve practical problems.
Dialing method:
Subtraction by abdication is not difficult. You only need to align the numbers to do subtraction.
If the single digits are small enough, ten people can borrow one.
10 minus 1 Yes 10. Let me calculate the minus 10.
How to reduce ten digits? Ten digits have been reduced again and again.