Partial product is a method of doing multiplication in math. The reason it’s called “partial product” or “partial answer” (the word “product” means answer in multiplication just like “sum” means answer in addition) is because you are doing many “parts” of a larger multiplication. To get to the final answer, you must add up all “parts”.
Besides breaking down the multiplication process into parts, another focus of partial product method is to write the number into its place values. In other words, all numbers (with the exception of the number in the one value) will end in zero – which makes multiplication easier and faster.
Here’s an example:
123
x 4
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Rewrite or breakdown 123 as 100 + 20 + 3
**The number 4 doesn’t need to be rewrite because it’s in the one value.**
Multiply each of the above value to 4 and you get:
100 x 4 = 400
20 x 4 = 80
3 x 4 = 12
Add the products/answers together, and you’ll get = 492
Check your answer by multiplying 123 x 4 = 492
Here’s another example:
45
x 78
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Rewrite 45 as 40 + 5
Rewrite 78 as 70 + 8
Multiply the top row of numbers to the bottom row of numbers:
40 x 70 = 2800
40 x 8 = 320
5 x 70 = 350
5 x 8 = 40
Add the products/answers together = 3510
Check your answer by multiplying 45 x 78 =3510
Hope this helps!
