Decimals are cool because you can add zeros to the end of them, and they will still be the same number.
16.43 = 16.430
I add the zero to the thousandths place because I am subtracting a number from 16.430 that has a number in the thousandths place. When you line the two numbers up to subtract you want to make sure they have an equal amount of decimal places.
1 6. 4 3 0 <— you now are ready to subtract.
- 1 . 0 4 3 I lined up the numbers in the
—————— ones, tenths, hundredths + Thousandths place. I drop the decimal point down.
Start from the rightmost digit.
You can’t subtract 3 from 0, so you borrow ten from the left.
3-1 =2. Cross out 3 and write 2 above it.
You add 10 to 0. 10+0=10. Cross out 0 and write 10 above it.
You can subtract 3 from 10 now. 10-3=7.
2 10
1 6. 4 3 0 You now have this.
- 1 . 0 4 3
——————
. 7
You can’t subtract 4 from 2, so you borrow from the left again.
4-1=3. Cross out 4 and write 3 above it. 2+10=12. Cross out 2 and write 12 above it.
12 - 4 = 8.
This is what that looks like:
12
3 2 10
1 6. 4 3 0 You now have this.
- 1 . 0 4 3
——————
. 8 7
3 - 0 = 3.
6 - 1= 5.
1 - 0 (as there is no digit in the tenths place) = 1
12
3 2 10
1 6. 4 3 0 You now have this.
- 1 . 0 4 3
——————
1 5. 3 8 7
So 16.43-1.043= 15.387