Multiplication Methods
1. The Column Method
You will no doubt be familiar with the column method for multiplication. Have you
wondered why it works?
Look at the solution above. What is actually happening during the solution? Why are there
two lines to be added together?
Using the sum above, fill in the gaps:
325 x 37 =
?? x ??
+
?? x ??
= 2275 + 9750 = 12025
Using the same idea as above, what multiplication sums would you add together for these
problems?
1.
2.
3.
4.
5.
6.
245
328
443
921
759
428
?
×
×
×
×
×
×
64 = ?×? + ?×?
41 = ?×? + ?×?
86 = ?×? + ?×?
11 = ?×? + ?×?
75 = ?×? + ?×?
121 = ?×? + ?×? + ?×
7. 476
?
8. 659
?
9. 777
?
10. 879
× 245 = ?×? + ?×? + ?×
× 386 = ?×? + ?×? + ?×
× 821 = ?×? + ?×? + ?×
× 323 = ?×? + ?×? + ?×?
Now practice the column method using the attached sheet and/or try the tricky puzzles
below:
2. The Grid Method
This method is very similar to the column method. Take a look at this example
What was the original sum?
Just like with the column method, the original sum is broken down into smaller sums,
which are then added together.
Complete the sum below using the example above:
?? x ?? = 20 x 30 + 20 x 5 + 6 x ?? + 6 x ?? = 910
Now practice the grid method using the attached sheet and/or try the tricky puzzles
below:
x
20
600
5
x
25
50
150
7
x
2
21
90
360
14
3. The Lattice Method
Below is the lattice method for solving 24 x 36.
This method may seem confusing at first, but again, it’s the same idea as the other
methods.
This video explains it very well.
Each diagonal (dotted) line shows either the units, tens, hundreds or thousands.
So 24 x 36 is broken down into: (4 x 30) + (20 x 30) + (20 x 6) + (4 x 6)
Try these lattice multiplications: