2. Multiplying Whole Numbers
Lesson 2-2

3. Example: 563 x 37 1 4 2
563 x 37 1 1 39 4 1 1 + 16 8 9 2 8 3 1

4. Example: 53 x 2618
2618 has more digits (4) than 53 (3), so it goes on top. 3 4 1 2
2618 x 53 1 7 8 5 4 13 9 + 1 3 8 7 5 4

6. Lattice Multiplication
Step-by-Step

7. I don’t remember how to multiply!!!
356 x 25 =
I don’t remember how to multiply!!!

8. I can help!! Let me show you how to do Lattice Multiplication.

9. 356 x 25
Make a grid the exact size of your problem. A 2 digit number times a 3 digit number gets a 2 x 3 grid. Draw a diagonal line in each box. 5 3 6 2 5

10. Multiply 6 * 2 and place the answer in the grid where the lines meet.
356 x 25
Multiply 6 * 2 and place the answer in the grid where the lines meet. 5 3 6 1 2 2 5

11. Multiply 5 * 2 and place the answer in the grid where the lines meet.
356 x 25
Multiply 5 * 2 and place the answer in the grid where the lines meet. 5 3 6 1 1 2 2 5

12. 356 x 25
Multiply 3 * 2 and place the answer in the grid where the lines meet. Use a zero as a place holder. 5 3 6 1 1 2 6 2 5

13. Multiply 6 * 5 and place the answer in the grid where the lines meet.
356 x 25
Multiply 6 * 5 and place the answer in the grid where the lines meet. 5 3 6 1 1 2 6 2 3 5

14. Multiply 5 * 5 and place the answer in the grid where the lines meet.
356 x 25
Multiply 5 * 5 and place the answer in the grid where the lines meet. 5 3 6 1 1 2 6 2 2 3 5 5

15. Multiply 3 * 5 and place the answer in the grid where the lines meet.
356 x 25
Multiply 3 * 5 and place the answer in the grid where the lines meet. 5 3 6 1 1 2 6 2 1 2 3 5 5 5

16. 356 x 25
Now add the diagonals and place the answer below the grid. Be sure to carry to the next diagonal if you have a 2 digit answer. 5 3 6 1 1 2 6 2 1 2 3 5 5 5

17. 356 x 25
Now add the diagonals and place the answer below the grid. Be sure to carry to the next diagonal if you have a 2 digit answer. 5 3 6 1 1 +1 2 6 2 1 2 3 5 5 5

18. 356 x 25
Now add the diagonals and place the answer below the grid. Be sure to carry to the next diagonal if you have a 2 digit answer. 5 3 6 1 1 +1 2 6 2 1 2 3 5 5 5 9

19. 356 x 25
Now add the diagonals and place the answer below the grid. Be sure to carry to the next diagonal if you have a 2 digit answer. 5 3 6 1 1 +1 2 6 2 1 2 3 5 8 5 5 9

20. 356 x 25
Now add the diagonals and place the answer below the grid. Be sure to carry to the next diagonal if you have a 2 digit answer. 5 3 6 1 1 +1 2 6 2 1 2 3 5 8 5 5 9

21. 356 x 25 =
8,900

22. Which method do you prefer?