The document provides step-by-step instructions for performing lattice multiplication with decimals. It demonstrates multiplying 3.42 by 6.9 using a lattice method. The steps include drawing a grid, placing the numbers in the grid with decimals aligned, multiplying the numbers and placing results in the grid, adding the diagonals while carrying numbers, and finally placing the decimal point to get the final answer of 23.598.

1. Lattice Multiplication
Step-by-Step

2. 356 * 25 =
I don’t
remember how
to multiply!!!

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

4. 356 * 25
3 5 6
2
5
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. 356 * 25
3 5 6
2
5
1
2
Multiply 6 * 2 and place the answer in the grid where the lines meet.

6. 356 * 25
3 5 6
2
5
1
20
1
Multiply 5 * 2 and place the answer in the grid where the lines meet.

7. 356 * 25
3 5 6
2
5
1
20
1
6
0
Multiply 3 * 2 and place the answer in the grid where the lines meet. Use a zero
as a place holder.

8. 356 * 25
3 5 6
2
5
1
20
1
6
0
0
3
Multiply 6 * 5 and place the answer in the grid where the lines meet.

9. 356 * 25
3 5 6
2
5
1
20
1
6
0
0
3
Multiply 5 * 5 and place the answer in the grid where the lines meet.
5
2

10. 356 * 25
3 5 6
2
5
1
20
1
6
0
0
3
Multiply 3 * 5 and place the answer in the grid where the lines meet.
5
2
5
1

11. 356 * 25
3 5 6
2
5
1
20
1
6
0
0
3
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
2
5
1
0

12. 356 * 25
3 5 6
2
5
1
20
1
6
0
0
3
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
2
5
1
00
+1

13. 356 * 25
3 5 6
2
5
1
20
1
6
0
0
3
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
2
5
1
00
+1
9

14. 356 * 25
3 5 6
2
5
1
20
1
6
0
0
3
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
2
5
1
00
+1
9
8

15. 356 * 25
3 5 6
2
5
1
20
1
6
0
0
3
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
2
5
1
00
+1
9
8

16. 356 * 25 =
8,900
That is Soooo
Cool!!!
Thanks!

17. Lattice Multiplication
with Decimals
Step-by-Step

18. 3.42 * 6.9 =
Ok! I know how to do
Lattice, but I don’t
remember how to
multiply with
decimals!!!

19. 3.42 * 6.9
3 4 2
6
9
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.

20. 3.42 * 6.9
3 4 2
6
9
Place the decimal point above/beside the line in the grid.
.
.

21. 3.42 * 6.9
3 4 2
6
9
1
2
Multiply 6 * 2 and place the answer in the grid where the lines meet.
.
.

22. 3.42 * 6.9
3 4 2
6
9
1
24
2
Multiply 4 * 6 and place the answer in the grid where the lines meet.
.
.

23. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
Multiply 3 * 6 and place the answer in the grid where the lines meet. Use a zero
as a place holder.
.
.

24. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
Multiply 2 * 9 and place the answer in the grid where the lines meet.
.
.

25. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
Multiply 4 * 9 and place the answer in the grid where the lines meet.
6
3
.
.

26. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
Multiply 3 * 9 and place the answer in the grid where the lines meet.
6
3
7
2
.
.

27. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
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.
6
3
7
2
8
.
.

28. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
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.
6
3
7
2
89
.
.

29. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
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.
6
3
7
2
89
+1
5
.
.

30. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
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.
6
3
7
2
89
+1
5
3
.+1
.

31. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
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.
6
3
7
2
895
3
. +1+1
2
.

32. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
Now you need to place the decimal. Follow the lines until they meet.
6
3
7
2
895
3
. +1+1
2
.

33. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
Now drop on the diagonal to place the decimal.
6
3
7
2
895
3
. +1+1
2
.
.

34. 3.42 * 6.9
3 4 2
6
9
1
24
2
8
1
8
1
Your answer is 23.598!!
6
3
7
2
895
3
. +1+1
2
.
.

35. 3.42 * 6.9=
23.598
That is Soooo
Cool!!!
Thanks!