Rounding and Decimals:

Subtraction with Larger Numbers

When doing subtraction with numbers that are too large to do in our heads, we have steps, or a pattern to follow, to help us do the subtraction correctly.

Steps for Subtraction (Whole Numbers)

Put the bigger number on top of the smaller number.
Stack the numbers so the digits are in columns according to their place value.
Regroup when needed.
Subtract starting with the column on the right and go left.

Regrouping
Regrouping is a way to subtract a larger number from a smaller number within the same place value column. It is done by taking 10 away from the place value to the left and adding that 10 to the number that needs to be bigger on the right.

Video Source (03:22 mins) | Transcript

Video Source (06:12 mins) | Transcript)

Additional Resources

Review: Steps for Subtraction (Whole Numbers) (04:53 mins, Transcript)
Khan Academy: Relate place value to standard algorithm for multi-digit subtraction (06:37 mins)

Practice Problems

Evaluate the following expression:

\(64-32=?\)
\(357-34=?\)
\(963-69=?\)
\(884-500=?\)
\(800-263=?\)
\(577-284=?\)
\(954-597=?\)

Solutions

32 (Written Solution)

Using place value to subtract, put the 6 in the tens place and the 4 in the ones place.

Next, put the 3 in the tens place and the 2 in the ones place.

Subtract the numbers in the ones place.

4 − 2 = 2

Finally, subtract the numbers in the tens place.

6 − 3 = 3

The answer is: 64 − 32 = 32
323 (Written Solution)

Using place value to subtract. Place the 3 in the hundreds place, the 5 in the tens place and the 7 in the ones place.

Now, place the 3 in the tens place and the 4 in the ones place.

Subtract the numbers in the ones place column. 7 − 4 = 3

Subtract the numbers in the tens place column. 5 − 3 = 2

Subtract the numbers in the hundreds column. Since 3 is the only number in this column, the answer is 3. Or in other words, 3 subtract 0 is 3.

The answer to 357 − 34 is 323.
894
384
537 (Solution Video | Transcript)
293
357 (Solution Video | Transcript)