Fractions of a whole
Understand a fraction 1/b as the quantity formed by 1 part when a whole is partitioned into b equal parts; understand a/b as a parts of size 1/b
What a learner can do afterwards
- Given a shape divided into 5 equal parts, identify one shaded part as 1/5
- Explain that 3/4 means 3 parts each of size 1/4
- Draw a model showing 2/6 as 2 pieces of a whole cut into 6
The lesson
You already know how to split a shape into equal parts and how to write a fraction like 3/4. Now let's look at what those numbers actually mean. When you cut a whole into b equal parts, one single part is called 1/b.
Alex cuts a pizza into 6 equal slices. Each slice is 1/6 of the pizza. Alex takes 4 slices, so that's 4 parts of size 1/6, or 4/6 of the pizza.
The bottom number tells you how many equal parts the whole is cut into. The top number tells you how many of those parts you have. Change the top number, and you have more or fewer parts. Change the bottom number, and the parts change size.
A fraction a/b means the whole is cut into b equal parts, and you have a of those parts.
Watch it
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.