คำตอบ - Long subtraction
21.9
คำอธิบายทีละขั้นตอน
1. Rewrite the numbers from top to bottom, aligned by their place values
| Place value | tens | ones | . | tenths |
| 3 | 6 | . | 7 | |
| - | 1 | 4 | . | 8 |
| . |
2. Subtract the numbers using long subtraction method
Because the upper digit (7) in the tenths column is too small to get a positive difference, borrow 1 from the digit (6) in the next number place which becomes (5) and get (17).
| Place value | tens | ones | . | tenths |
| 5 | 17 | |||
| 3 | 6 | . | 7 | |
| - | 1 | 4 | . | 8 |
| . |
Subtract the numbers in the tenths column from the top number:
17-8=9
| Place value | tens | ones | . | tenths |
| 5 | 17 | |||
| 3 | 6 | . | 7 | |
| - | 1 | 4 | . | 8 |
| . | 9 |
Subtract the numbers in the ones column from the top number:
5-4=1
| Place value | tens | ones | . | tenths |
| 5 | 17 | |||
| 3 | 6 | . | 7 | |
| - | 1 | 4 | . | 8 |
| 1 | . | 9 |
Subtract the numbers in the tens column from the top number:
3-1=2
| Place value | tens | ones | . | tenths |
| 5 | 17 | |||
| 3 | 6 | . | 7 | |
| - | 1 | 4 | . | 8 |
| 2 | 1 | . | 9 |
The solution is: 21.9
ทำไมต้องเรียนสิ่งนี้
Learn more with Tiger
Why learn this