2. Before learning how to do double digit multiplication, let’s review what multiplication is...

3. Let’s choose a problem:

4. 15 * 17 means: 15 groups of 17or 17+17+ 17+ 17+ 17+ 17+ 17+ 17+ 17+ 17

5. base ten blocks To solve 15 * 17, we can use base ten blocks to find the answer...

6. Devin and Peter are building 15 groups or rows of 17.

7. Emily and Travis use a corner piece to line up their problem in neat rows and columns.

8. Kevin and Patrick decide to use rods to show “tens” and unit cubes to show “ones.”

9. Alyssa Erin

10. Jordan Michael

12. 15 groups or rows 17 in each group

13. 15 17

14. 4 different products Now that you have built 15 * 17, you can see the 4 different products that are created:

15. 10 + 7 + 5 10 * 10 = 10 * 7 = 5 * 10 = 5 * 7 =

16. 100 70 50 + 35 255 If we add up all of the products, we get:

17. building draw By building the multiplication problem, we can see the answer beautifully, but it does take a lot of time and materials to do so. A shorter method is to draw the multiplication problem using graph paper...

18. Erin lines up 15 rows and 17 columns on graph paper.

19. Devin extends the lines and colors each of the four sections in a different color.

20. Kevin shows what 15 * 17 looks like as a picture. Did he get the same answer?

21. Here is the picture for 15 * 17. Notice that there are 15 rows of 17 & that 4 sections are created by this problem:

22. Do we get the same answer? 100 70 50 + 35 255

24. Drawing a picture of a multiplication problem works, too, but it does take time to draw and color the picture. Is there a shorter way?

26. 15 * 17 should remind you of MULTIPLICATION WRESTLING!

27. Do these numbers look familiar?

28. Multiplication Wrestling other So you can solve double digit multiplication problems using Multiplication Wrestling, but there are other ways, too...

29. PARTIAL PRODUCTS: One shortcut method is called PARTIAL PRODUCTS:

30. These numbers should look familiar!

31. SHORTCUT METHOD... Another method is called the SHORTCUT METHOD...

32. 35 + 50 70 + 100 These numbers should look familiar!

33. “There’s more than one way to skin a cat!” There are many ways to solve Double Digit Multiplication problems. Choose the method that works for you. “There’s more than one way to skin a cat!”