How to Subtract

Step-by-Step Guide

1. 1

   Step 1: Write down the larger number.

   Let's say you're working with the problem 32
   -
   17.
   
   Write down 32 first.
2. 2

   Step 2: Write the smaller number directly below it.

   Make sure that you line up the tens and ones columns, so that the 3 in "32" is directly above the 1 in "17" and that the 2 in "32" is directly above the "7" in
   17. , Now, this can get a little bit tricky when the bottom number is larger than the top number.
   
   In this case, 7 is larger than
   2.
   
   Here's what you need to do:
   You'll need to "borrow" from the 3 in "32" (also known as regrouping), in order to turn that 2 into a
   12.
   
   Cross off the 3 in "32" and make it a 2, while making the 2 a
   12.
   
   Now, you have 12
   - 7, which is equal to
   5.
   
   Write a 5 below the two numbers you subtracted, so it lines up with the ones column in a new row. , Remember that your 3 is now a
   2.
   
   Now, subtract the 1 in 17 from the 2 above it to get (2-1)
   1.
   
   Write 1 below the numbers in the tens columns, to the left of the 5 in the ones column of the answer.
   
   You should have written
   15.
   
   This means that 32
   - 17 =
   15. , If you want to be sure that you correctly subtracted the two numbers, then all you have to do is to add the answer to the smaller number to make sure that you get the larger number.
   
   In this case, you should add your answer, 15, to the smaller number in the subtraction number,
   17. 15 + 17 = 32, so you've done your work correctly.
   
   Well done!
3. 3

   Step 3: Subtract the number in the ones column of the bottom number from the number in the ones column of the top number.

4. 4

   Step 4: Subtract the number in the tens column of the bottom number from the number in the tens column of the top number.

5. 5

   Step 5: Check your work.

Detailed Guide

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