Decimals and fractions (age 10+)
Associate a fraction with division and calculate decimal fraction equivalents for simple fractions (e.g. 3/8 = 0.375); recall and use equivalences between simple fractions, decimals, and percentages in different contexts
What a learner can do afterwards
- Convert 3/8 to 0.375 by dividing 3 ÷ 8
- State that 1/5 = 0.2 = 20% from memory
- Use fraction–decimal–percentage equivalences to compare 30%, 1/3, and 0.35 and put them in order
The lesson
A fraction is really a division in disguise. 3/8 means exactly the same thing as 3 divided by 8. Do that division, and you get a decimal that stands for the same amount.
To find 3 ÷ 8, add a decimal point and zeros after the 3. 30 ÷ 8 = 3, remainder 6. Bring down a zero: 60 ÷ 8 = 7, remainder 4. Bring down another zero: 40 ÷ 8 = 5, no remainder left. Put it together: 0.375.
A decimal and a percent are two ways to say the same amount. Move the decimal point two places to the right to get a percent, so 0.375 becomes 37.5%.
When you compare a percent, a fraction, and a decimal, like 30%, 1/3, and 0.35, turn them all into decimals first. 30% is 0.30, 1/3 is about 0.333, and 0.35 stays as it is. Lined up smallest to largest: 0.30, 0.333, 0.35.
A fraction is a division: work it out, and you get the matching decimal and percent.
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.