Lesson 4 — Activity 4: Multiplying Decimals
Completion requirements
Lesson 4 — Activity 4:
Multiplying Decimals
If you can multiply whole numbers, then you can multiply numbers with decimals. The process is the same!
- Multiply the numbers as if there were no decimals.
- Count the number of decimal places in your question.
- Starting at the right side of the answer, move an imaginary decimal point to the left for the number of decimal places counted in the above step.
Remember: Multiplying numbers with decimals uses the same process as multiplying whole numbers.
Practice the Process!
Apples cost $0.35 each. You need 15 for a large apple dessert.
1. Multiply the numbers as if there were no decimals.
0.35
x 15
175
+350
525
2. Count the number of decimal places in your question (there are 2).
3. Starting at the right side of the answer, move an imaginary decimal point to the left for the number of decimal places counted in the above step.
The answer is 5.25 — and that's $5.25.
Did you know ...
When you multiply decimals by 10, 100, 1,000, etc. you can move the decimal to the right. The zeros are used as place holders.
2.5 x 10 = 25
(The decimal is moved one place to the right.)
2.5 x 100 = 250
(The decimal is moved two places to the right.)
2.5 x 1,000 = 2,500
(The decimal is moved three places to the right.)
Self-check!
Try this!