Subtraction with Borrowing By Mrs. Cupples
So let’s say that we start with the following math problem‌
574 - 396
574 - 396 Start at the Ones Place. Since we cannot do 4 – 6, we need to borrow from the tens place.
574 - 396 So the 4 went right next door to see if the 7 had something to borrow.
4 7
6 1 574 \
- 396
6
1 4 7\
The 7 said, “Sure!! Take one! And since I am in the tens place, I am worth 10 for you!“ The 7 became a 6… and the 4 went back home as a 14.
6 1 574 \
- 396
Next we look at the Tens Place. We can’t do 6 – 9, so again we have to borrow. So the 6 goes next door to the Hundreds Place.
5 164
4 16 1 574\ \
- 396
4
The 5 is happy to help, so the 5 becomes a 4 and the 6 becomes a 16!
1 6 5\
We now have enough in each column to subtract!! Thanks to our neighbors right next door. ď Š
So first in the Ones Place we had to borrow from the Tens Place. The 7 became a 6 and the 4 became a 14. Then we had to borrow from the Hundreds Place because we don’t have enough in the Tens Place. The 5 becomes a 4 and the 6 becomes a 16. Now we can finally subtract each column to find our answer.
4 16 1 \\ 574
- 396
1 78
14 – 6 =
16 – 9 = 4–3=
574 - 396 1 78
Now don’t forget that you can ALWAYS add to double check your subtraction!! Your bottom two numbers should add up to the top number that you started with.
Let’s try that next….
First we take the two numbers to add.
574 - 396 1 78
If your two numbers match, you are right!! If not, you need to go back and see where you made a mistake. ď Š
Start at the Ones Place, at 6 + 8 which = 14. Write down the 4 and carry the 1. Next go to the Tens Place and see that 9 + the 1 that you carried, make 10 + the 7 = 17. Write down the 7 and carry the 1.
11
396 + 178 57 4
Finally add the Hundreds Place to find that 3+1+1=5
Great Job!! Now you can apply that to other Subtraction Problems, and become a pro!! ď Š