Multiplying with Arrays
Learning Objective
I can solve multiplication problems with 2-digit numbers using arrays.
Key Concepts
When multiplying 37 × 26, we can break it down into (30 × 6) + (7 × 6) + (30 × 20) + (7 × 20), which equals 180 + 42 + 600 + 140.
Multiplying 37 × 26 can be thought of as finding the sum of 37 sixes and 37 twenties.
When multiplying two 2-digit numbers using partial products, it's helpful to stack the numbers by their place value to keep track of the ones, tens, and hundreds.
Practice Questions
This lesson includes 3 practice questions to reinforce learning.
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1. Break down 24 x 15 into smaller multiplication problems based on place value. What two multiplications involving multiples of 10 will you need to solve?
2. Solve 15 x 12 using the method from the video. Show each step, breaking the numbers into tens and ones and multiplying each part separately.
3. Which expression represents how to solve 45 x 23 by breaking down each number by its place value?
Educational Video
Multiplying two 2-digit numbers using partial products
Khan Academy