Lesson 1.5, Part 2
In this post, we’ll be using the “Vertically and Crosswise” method of multiplying. We’ll be dealing with two 2-digit numbers.
How to use Vertically and Crosswise
Steps correspond to the picture below. In steps 3 & 4, if you end up with a number that has more than one-digit, you write the last digit down and carry the other digits to the left.
1) Write the two numbers out, one above the other.
2) Multiply the left-hand column vertically.
3) Cross multiply and add.
4) Multiply the right-hand column vertically.
(CLICK IMAGE TO ENLARGE)
Practice Problems:
1. 15 2. 17 3. 27 4. 32 5. 45
12 15 22 21 13
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6. 48 7. 61 8. 79 9. 92 10. 99
24 53 68 91 97
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Other Parts of Lesson 1.5:
Part 1 – Intro. to “Vertically and Crosswise”
Part 3 – Three-Digit Multiplication
Part 4 – Extending to any number of Digits
Part 5 – Algebraic Multiplication
Part 6 – Extra Problems
[...] Parts of Lesson 1.5: Part 2 – Two-Digit Multiplication Part 3 – Three-Digit Multiplication Part 4 – Extending to any number of Digits Part 5 – Algebraic [...]
Oh, this is wonderful!
This is just about the right length of a post compared to what you were posting before.
Thank you for taking the time to do this!
Madame Monet
Writing, Painting, Music, and Wine
winewriter.wordpress.com