คำตอบ - Long subtraction
คำอธิบายทีละขั้นตอน
1. Rewrite the numbers from top to bottom, aligned by their place values
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 1 | 2 | . | 3 | 2 | ||
| - | 9 | . | 1 | 4 | 7 | |
| . |
Put zeros in the blank number places:
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 1 | 2 | . | 3 | 2 | 0 | |
| - | 9 | . | 1 | 4 | 7 | |
| . |
2. Subtract the numbers using long subtraction method
Because the upper digit (0) in the thousandths column is too small to get a positive difference, borrow 1 from the digit (2) in the next number place which becomes (1) and get (10).
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 1 | 10 | |||||
| 1 | 2 | . | 3 | 2 | 0 | |
| - | 9 | . | 1 | 4 | 7 | |
| . |
Subtract the numbers in the thousandths column from the top number:
10-0-7=3
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 1 | 10 | |||||
| 1 | 2 | . | 3 | 2 | 0 | |
| - | 9 | . | 1 | 4 | 7 | |
| . | 3 |
Because the upper digit (1) in the hundredths column is too small to get a positive difference, borrow 1 from the digit (3) in the next number place which becomes (2) and get (11).
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 2 | 11 | |||||
| 1 | 10 | |||||
| 1 | 2 | . | 3 | 2 | 0 | |
| - | 9 | . | 1 | 4 | 7 | |
| . | 3 |
Subtract the numbers in the hundredths column from the top number:
11-4=7
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 2 | 11 | |||||
| 1 | 10 | |||||
| 1 | 2 | . | 3 | 2 | 0 | |
| - | 9 | . | 1 | 4 | 7 | |
| . | 7 | 3 |
Subtract the numbers in the tenths column from the top number:
2-1=1
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 2 | 11 | |||||
| 1 | 10 | |||||
| 1 | 2 | . | 3 | 2 | 0 | |
| - | 9 | . | 1 | 4 | 7 | |
| . | 1 | 7 | 3 |
Because the upper digit (2) in the ones column is too small to get a positive difference, borrow 1 from the digit (1) in the next number place which becomes (0) and get (12).
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 0 | 12 | |||||
| 2 | 11 | |||||
| 1 | 10 | |||||
| 1 | 2 | . | 3 | 2 | 0 | |
| - | 9 | . | 1 | 4 | 7 | |
| . | 1 | 7 | 3 |
Subtract the numbers in the ones column from the top number:
12-9=3
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 0 | 12 | |||||
| 2 | 11 | |||||
| 1 | 10 | |||||
| 1 | 2 | . | 3 | 2 | 0 | |
| - | 9 | . | 1 | 4 | 7 | |
| 3 | . | 1 | 7 | 3 |
Write 0 in the tens place.
| Place value | tens | ones | . | tenths | hundredths | thousandths |
| 0 | 12 | |||||
| 2 | 11 | |||||
| 1 | 10 | |||||
| 1 | 2 | . | 3 | 2 | 0 | |
| - | 9 | . | 1 | 4 | 7 | |
| 0 | 3 | . | 1 | 7 | 3 |
The solution is: 3.173
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