Using Only Digits to Subtract with Regrouping

Question

Subtract: 131 - 12

Write the numbers vertically.
Line these numbers up by _.
Regroup a ten to make more ones.
Our answer is _.

Answer 1

To solve the subtraction problem \(131 - 12\) using only digits and regrouping, we'll follow the steps below.

1. Write the numbers vertically, aligning them by place value:

  131
-  12

2. We need to subtract the ones column first. In this case, we have 1 in the ones place of the top number and 2 in the ones place of the bottom number. Since we cannot subtract 2 from 1, we will regroup:

• We will take 1 ten (which is 10) from the tens place (3 in 131) and add it to the ones place of 131. So, the 1 in the ones place becomes \(1 + 10 = 11\), and the 3 in the tens place becomes \(3 - 1 = 2\).

Now the numbers look like this:

  121   (the 1 in the ones column becomes 11; the 3 in the tens column becomes 2)
-  12

3. Now we can perform the subtraction.

   • In the ones place: \(11 - 2 = 9\)
   • In the tens place: \(2 - 1 = 1\)
   • In the hundreds place: \(1 - 0 = 1\)

4. Therefore, our final answer is:

  131
-  12
_____
  119

So, our answer is 119.