---
title: "Understanding Percentages"
description: "Understand the per cent symbol (%); know that per cent means ‘number of parts per hundred’; write percentages as a fraction with denominator 100 and as a decimal"
canonical: https://lightmysky.com/learn/mathematics/understanding-percentages-mt_ZM9mhHsyYZ
source: https://lightmysky.com/learn/mathematics/understanding-percentages-mt_ZM9mhHsyYZ.md
retrieved: 2026-10-19
---

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# Understanding Percentages

Understand the per cent symbol (%); know that per cent means ‘number of parts per hundred’; write percentages as a fraction with denominator 100 and as a decimal

Subject: Mathematics · Area: Fractions · Ages 9 to 10
Page: https://lightmysky.com/learn/mathematics/understanding-percentages-mt_ZM9mhHsyYZ

## Ready when they can

- Write 35% as 35/100 and as 0.35
- Shade 40% of a 10×10 grid and write the fraction 40/100
- Explain that 100% means the whole, 50% means half

## Lesson: What Percent Means

The symbol % is called percent. Percent means 'out of 100.' When you see 35%, it means 35 out of every 100 equal parts. You already know how to write hundredths as decimals, so percent gives you a new way to write the same amount.

*(drawing: Picture a grid of 100 equal squares. 40 of them are shaded. That's 40%, which is 40/100, or 0.40.)*

**Example.** Look at 35%. Since percent means out of 100, you can write it as the fraction 35/100. A fraction with 100 on the bottom is also a decimal with two digits after the point, so 35/100 is the same as 0.35.

**Tip.** 100% means the whole thing, all 100 parts. 50% means half, since 50 is half of 100. Whenever you see percent, ask yourself: how many parts out of 100?

**Recap.** Percent means out of 100: write it as a fraction over 100, then as a decimal by counting two places.

## Practice

14 questions on this page, each with its working shown.

## Needs first

- [Decimals for Tenths & Hundredths](https://lightmysky.com/learn/mathematics/decimals-for-tenths-and-hundredths-mt_Vi4Vo5xs_g)
- [Decimal & Percent Notation](https://lightmysky.com/learn/mathematics/decimal-and-percent-notation-mt_W17Kbwm0-u)

## Opens up

- [Decimals and fractions (age 10+)](https://lightmysky.com/learn/mathematics/decimals-and-fractions-age-10-mt_4K1dr204Hi)
- [Percentage and decimal equivalents](https://lightmysky.com/learn/mathematics/percentage-and-decimal-equivalents-mt_4ubP_RMg9o)
- [Moving between bar models, number lines and equations](https://lightmysky.com/learn/mathematics/moving-between-bar-models-number-lines-and-equations-mt_CUmjcE7W6c)
- [Ratio and proportion vocabulary](https://lightmysky.com/learn/mathematics/ratio-and-proportion-vocabulary-mt_ESgc4YBw-a)