LATTICE MULTIPLICATION

Tutorial 4

At the end of Tutorial 3 I gave you a problem to work on independently. Watch as I use LATTICE

MULTIPLICATION to solve that problem.

Tutorial 3’sOn Your Own Problem:

93 x 5 =

First, write the larger number down.

9 3

Draw a rectangle below this number.

9 3

The larger number is made up of 2 digits, so cut the rectangle into

two boxes.

9 3

Write the other problem number on the right of

the rectangle.

59 3

Cut the boxes diagonally. For each box draw a line from the bottom left to

the top right.

59 3

Now we do basic multiplication. Start with the 9. If we go

down from the 9 and across from the 5 they

“meet” in that first box.

59 3

9 x 5 = 4 5Write 4 in the top half of

the box and write 5 in the bottom half of the

box.

45 5

9 3

Move on to the 3. If we go down from the 3 and across from the 5 they “meet” in that second

box.

59 3

45

3 x 5 = 1 5 Write 1 in the top half of

the box and write 5 in the bottom half of the

box.

45

15 5

9 3

Extend your diagonal lines down.

45

15 5

9 3

Add the numbers inside the boxes. Use the diagonal lines

to guide you. Start on the right with the 5 then move to the left. 5 + nothing = 5. So put a 5 on the right of

the diagonal lines.

45

15 5

9 3

5

1 + 5 = 6. So put a 6 between the diagonal

lines.

45

15 5

9 3

56

4 + nothing = 4. So put a 4 to the left of the

diagonal lines.

45

15 5

9 3

564

That’s it!465 is your answer.

9 3 x 5 = 4 6 5

ON YOUR OWNTry the following

problem using the rules from today’s work. The answer will be the first

thing given in TUTORIAL 5.

On Your Own Problem:

82 x 4 =