Area of rectangles – Grade 3 math lesson
US version. US grades, US spelling and dollars ($). · UK version (Year 4)
A complete 45-minute lesson for grade 3 (ages 8–9) that runs on this page – at school or at home. Every answer is graded right away, with a worked explanation.
- Time
- 45 minutes + 15 min homework
- Grade
- Grade 3 (ages 8–9)
- You need
- Paper, a pencil and this page
- Graded
- Instantly, with explanations
For parents: how to use this lesson
You don't need to know this topic yourself. The lesson explains each step on screen, the way Mr Euclid, our Head of Math, likes it: one tidy step at a time. Every answer is graded straight away with a worked explanation, so you never have to grade anything.
- Read what your child will learn together.
- Press Start the lesson below and sit with your child for the teaching and the worked examples (about 19 minutes).
- Let them do the practice on their own. They choose Getting started, On track or Challenge – start on On track and move up after a few right in a row.
- Finish with the exit ticket and the talk question: “Can two rectangles have the same area but different shapes?”
- Later that day or the next day: the homework (15 minutes), then a practice test.
Watch out for
- Mixing up area and perimeter. Area is the inside (cover it with squares); perimeter is the outside edge.
- Adding the sides instead of multiplying. Draw the rectangle on squared paper and count the squares.
Miss Hypatia's tip for home: Measure a table or a rug and work out its area.
What your child will learn
Learning goal: find the area of rectangles.
Success looks like
- I can count squares to find an area.
- I can use length × width.
- I can split a shape into rectangles.
Key words
- area
- the space inside a flat shape
- square centimeter (cm²)
- a square 1 cm long and 1 cm wide
- length and width
- the two side lengths of a rectangle
- compound shape
- a shape made of more than one rectangle
What to have ready
- Paper and a pencil
- This page on a computer, tablet or phone
- For the hands-on part: Draw rectangles on squared paper with a given area (e.g. 24 squares). How many different rectangles can you make? No squared paper? Use counters laid out in rows.
The lesson, step by step
| Part | Time | How it is checked |
|---|---|---|
| Starter: quick recall | 5 min | Graded by Classfern |
| Teaching input | 10 min | Not assessed, self-checked |
| Worked examples and guided practice | 9 min | Not assessed, graded by Classfern |
| Independent practice | 15 min | Graded by Classfern |
| Closure and exit ticket | 6 min | Graded by Classfern, self-checked |
Starter, "your turn", practice and exit ticket are graded by Classfern. Worked examples and teaching are not assessed. The hands-on task and the reflection are self-assessed. Explanations in talk are judged by the parent and not recorded.
The lesson
It runs here on the page. No sign-up and no names – progress is kept only in this browser.
Homework and practice at home
15 minutes: 8 practice questions, 3 multiple-choice questions and 2 to remember from earlier work, then a short reflection. New questions every time, all graded instantly.
More practice
More Grade 3 math lessons
Curriculum
Common Core State Standards: ccss-ma-3-md-c-7-b
Our lessons and questions are our own. They are not written or endorsed by any government department, testing agency or exam board.