Math lesson plan · 6th grade (Year 7 in England) · 60 minutes
Substitute into everyday formulas
Algebra
CCSS 6.EE.A.2.CEngland: KS3 AlgebraEngland: GCSE Foundation Algebra
Objective and success criteria
Students will: Substitute into everyday formulas.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Evaluate expressions
Leads to: the next skill in this area.
Materials: Balance scales or a balance drawing, Algebra tiles, Function machine cards, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 6 min
- Quick retrieval from earlier learning (Evaluate expressions). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Find the value of 5x − 9 when x = 4. → 11Prompt: Replace x with 4.
- Evaluate x² + 2y when x = 5 and y = 2. → 29Prompt: Substitute each letter, using brackets around negative numbers.
- Convert 15 °C to °F using F = 9C/5 + 32. → 59Prompt: Multiply C by 9, divide by 5, then add 32.
Hook · 6 min
- Show a "think of a number" puzzle and ask the class to work out the starting number.
- Share the objective: Substitute into everyday formulas. Read the success criteria together.
I do: model it · 12 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: The perimeter of a rectangle is P = 2(l + w). Find P when l = 15 cm and w = 3 cm.
- Step 1: P = 2(15 + 3) = 2 × 18 = 36 cm
- Answer: 36
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 12 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- The perimeter of a rectangle is P = 2(l + w). Find P when l = 8 cm and w = 2 cm. → 20Prompt: Add inside the brackets first.
- To change °C to °F, use F = 1.8C + 32. What is 35 °C in °F? → 95Prompt: Multiply the Celsius temperature by 1.8 first.
You do: independent practice · 17 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 7 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- The surface area of a cube is A = 6s². Find A when s = 3 cm. → 54Prompt: Substitute the side length.
- A taxi fare is C = 3 + 2m (in dollars), where m is the number of miles. Find C for a 5-mile trip. → 13Prompt: Replace m with the number of miles.
Watch out for
- Doing an operation to one side of an equation but not the other.
- Reading 3x as 3 + x, or thinking x always stands for one particular number.
Support and stretch
Support
- Review first: Evaluate expressions.
- Use concrete materials: balance scales or a balance drawing.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/math/grade-6.
Free lesson plan from eurekami.com/lesson-plan-builder