Partial Product strategy
(Multiplication)
Partial product is when we use expanded form to solve multiplication problems.
Expanded form example: 419 = 400 + 10 + 9
EXAMPLE: If you had the multiplication problem
29 x 40 =
you would begin by
finding the expanded form of the number that is not a base of ten. (Base of ten
numbers, or multiples of 10, end in a zero.)
So, 29 broken into expanded form would be 20 + 9.
Now we have
20 x 40
and
9 x 40
You will find the product of each, then add them together to find your answer.
2x4
(how many zeroes do you have?)
20 x 40 = 800
9x4
9 x 40 = 360
Add the two
products
highlighted above
for your answer:
800
+ 360
1,160
ANSWER
Partial Product strategy – TWO DIGIT
(Multiplication)
If you have two 2-digit numbers you are multiplying with partial product, use the
FOIL strategy.
EXAMPLE:
54 x 63 =
1. Find the expanded form of each number and put them in parentheses:
(50 + 4) (60 + 3) =
2. Use the FOIL strategy to multiply.
FOIL stands for First, Outer, Inner, Last
We will multiply the first numbers in each set of parentheses, then the outer
numbers in each parentheses, the inner numbers and the last numbers in each
parentheses.
F: 50 x 60 = 3000
O: 50 x 3 =
150
I: 4 x 60 =
240
L: 4 x 3
=
12
Now, add the products (highlighted above) to find your answer.
3,000
150
240
+
12
3,402
ANSWER