Download presentation
Presentation is loading. Please wait.
Published byFelix Byrd Modified over 9 years ago
1
4th Grade Math Multiplying 2-digit by 2-digit Numbers Using the Area Model / Box Method
2
Slide 1 Here's the Problem Let's go with 23 x 45
3
Slide 3 Expanded Form 23 becomes 20 + 3 45 becomes 40 + 5
4
page 4 Drawing Time! Draw a window with 4 panels. 20 and 3 go on the top 40 and 5 go on the side
5
Okay, Let's Multiply! ❖ The top left square... ❖ Is under the 20... ❖ And beside the 40... ❖ So multiply 20 x 40 ❖ 800 in the 1st square
6
Square 2 ❖ The top right square... ❖ Is under the 3... ❖ And beside the 40 ❖ Multiply 3 x 40 ❖ 120
7
Down on the Corner ❖ Bottom left square... ❖ Under the 20... ❖ Beside the 5 ❖ 5 x 20 ❖ 100
8
The Last Panel ❖ The bottom right square... ❖ Is under the 3... ❖ And beside the 5 ❖ 3 x 5 ❖ 15
9
How much are those numbers in the Window? ❖ These 4 numbers are the partial products ❖ Add them together to get the final answer ❖ Thanks to the commutative property the order that you add them doesn't matter ❖ In this example, we are adding across first, then adding our two answers
10
Add it up! ❖ Adding the top row ❖ 800 + 120 ❖ 920
11
Bottoms Up! ❖ Adding the bottom Row ❖ 100 + 15 ❖ 115
12
Summing it Up ❖ Add the two sums together ❖ 920 + 115 ❖ 1,035
13
Almost the last page This is it! 23 x 45 = 1,035
14
This is the last page I hope this helps The end (Told you it was the last page)
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.