Post on 12-Apr-2017
Lattice MultiplicationStep-by-Step
356 * 25 =I don’t
remember how to multiply!!!
HELP!!! I can help!! Let me show you how to
do Lattice Multiplication.
356 * 25
3 5 62
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.
356 * 25
3 5 62
5
12
Multiply 6 * 2 and place the answer in the grid where the lines meet.
356 * 25
3 5 62
5
1201
Multiply 5 * 2 and place the answer in the grid where the lines meet.
356 * 25
3 5 62
5
1201
60
Multiply 3 * 2 and place the answer in the grid where the lines meet. Use a zero as a place holder.
356 * 25
3 5 62
5
1201
60
03
Multiply 6 * 5 and place the answer in the grid where the lines meet.
356 * 25
3 5 62
5
1201
60
03
Multiply 5 * 5 and place the answer in the grid where the lines meet.
52
356 * 25
3 5 62
5
1201
60
03
Multiply 3 * 5 and place the answer in the grid where the lines meet.
5251
356 * 25
3 5 62
5
1201
60
03
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.
5251
0
356 * 25
3 5 62
5
1201
60
03
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.
5251
00
+1
356 * 25
3 5 62
5
1201
60
03
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.
5251
00
+1
9
356 * 25
3 5 62
5
1201
60
03
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.
5251
00
+1
98
356 * 25
3 5 62
5
1201
60
03
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.
5251
00
+1
98
356 * 25 =8,900
That is Soooo Cool!!!
Thanks!
Lattice Multiplicationwith Decimals
Step-by-Step
3.42 * 6.9 =Ok! I know how to do
Lattice, but I don’t remember how to
multiply with decimals!!!
3.42 * 6.9
3 4 26
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.
3.42 * 6.9
3 4 26
9
Place the decimal point above/beside the line in the grid.
..
3.42 * 6.9
3 4 26
9
12
Multiply 6 * 2 and place the answer in the grid where the lines meet.
..
3.42 * 6.9
3 4 26
9
1242
Multiply 4 * 6 and place the answer in the grid where the lines meet.
..
3.42 * 6.9
3 4 26
9
1242
81
Multiply 3 * 6 and place the answer in the grid where the lines meet. Use a zero as a place holder.
..
3.42 * 6.9
3 4 26
9
1242
81
81
Multiply 2 * 9 and place the answer in the grid where the lines meet.
..
3.42 * 6.9
3 4 26
9
1242
81
81
Multiply 4 * 9 and place the answer in the grid where the lines meet.
63
..
3.42 * 6.9
3 4 26
9
1242
81
81
Multiply 3 * 9 and place the answer in the grid where the lines meet.
6372
..
3.42 * 6.9
3 4 26
9
1242
81
81
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.
6372
8
..
3.42 * 6.9
3 4 26
9
1242
81
81
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.
6372
89
..
3.42 * 6.9
3 4 26
9
1242
81
81
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.
6372
89
+1
5
..
3.42 * 6.9
3 4 26
9
1242
81
81
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.
6372
89
+1
53
.+1
.
3.42 * 6.9
3 4 26
9
1242
81
81
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.
6372
8953
.+1+1
2 .
3.42 * 6.9
3 4 26
9
1242
81
81
Now you need to place the decimal. Follow the lines until they meet.
6372
8953
.+1+1
2 .
3.42 * 6.9
3 4 26
9
1242
81
81
Now drop on the diagonal to place the decimal.
6372
8953
.+1+1
2 ..
3.42 * 6.9
3 4 26
9
1242
81
81
Your answer is 23.598!!
6372
8953
.+1+1
2 ..
3.42 * 6.9 =23.598
That is Soooo Cool!!!
Thanks!