3-Digit by 2-Digit Multiplication Challenge
16 problems on two pages, each a three-digit number times a two-digit number, stacked in columns. The products run to four and five digits. It's 5th grade work with the standard algorithm, and a stretch for 4th graders who have 2-digit by 2-digit down.
Worksheet Preview
Two partial products and a lot of carrying
For 719 × 25, multiply 719 by the 5 to get 3595. Then multiply 719 by the 2, which stands for 20, so that row is 14380, with a zero at the end. Adding the two rows gives 17975.
With three digits on top, each row can carry two or three times, and carries from the first row can get mixed into the second. Have students cross out the first row's carried digits before starting the second row.
Estimating catches most place value slips. 719 × 25 is about 700 × 25, or 17,500, so an answer in the 17,000s is on track.
Frequently Asked Questions
What grade learns 3-digit by 2-digit multiplication?
5th grade, when students are expected to multiply multi-digit whole numbers fluently with the standard algorithm.
Why does the second row end in a zero?
The second digit of the bottom number is in the tens place. Multiplying by the 2 in 25 really means multiplying by 20, and the zero keeps every digit of that row in the right place.
What's a good way to check the answer?
Estimate before and after. 317 × 94 is close to 300 × 100, or 30,000, so an answer of 29798 is reasonable. An answer near 3,000 would mean a missing zero.