Fraction of a number
Topic Notes
In this lesson, we will learn:
- How to understand fraction of a number using: models with shapes, models with fraction blocks, and fraction number lines
- The steps for multiplying a fraction with a whole number
Notes:
- When we are looking for a fraction of a number, we are using multiplication
- The word “of” in math usually signifies multiplication
- We can use models with shapes to find the fraction of a number:
- Ex. What is of 15?
- Use 15 circles to represent the whole number; divide into 5 equal parts; answer how many circles are in 1 of those parts:
![Introduction to Fractions: Fraction of a Number](
https://dmn92m25mtw4z.cloudfront.net/img_set/math5-8-4-x-1/v1/math5-8-4-x-1-247w.jpg)
- We can also use models with fraction blocks to find the fraction of a number:
- Ex. What is × 5?
- Create a fraction block with 2 of 3 equal parts shaded in. Repeat 5 times.
- There are 10 parts shaded in, each one is worth of a whole.
- Therefore, x 5 = or 3
- We can also use number lines to find the fraction of a number:
- Ex. What is 4 × ?
- Split a line (from 0 to 1) into 5 equal parts, create 4 jumps of 1 part each ()
![Introduction to Fractions: Fraction of a Number](
https://dmn92m25mtw4z.cloudfront.net/img_set/math5-8-4-x-2/v1/math5-8-4-x-2-817w.jpg)
![Introduction to Fractions: Fraction of a Number](
https://dmn92m25mtw4z.cloudfront.net/img_set/math5-8-4-x-3/v1/math5-8-4-x-3-704w.jpg)
- Generally, the fastest way to find the fraction of a number will be to do fraction multiplication with a whole number using these steps:
- Ex. What is of 24?
Step 1: Put the whole number as a fraction over 1
Step 2: Cross cancel the numbers if possible
Step 3: Multiply the top numbers and then separately multiply the bottom numbers
Step 4: Write your answer in lowest terms
![Introduction to Fractions: Fraction of a Number](
https://dmn92m25mtw4z.cloudfront.net/img_set/math5-8-4-x-4/v1/math5-8-4-x-4-320w.jpg)