Math lesson plan · 6th grade (Year 7 in England) · 45 minutes
Expand brackets with positive terms
Algebra
CCSS 6.EE.A.3England: KS3 Algebra
Objective and success criteria
Students will: Expand brackets with positive terms.
- 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: Recognise equivalent 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 · 5 min
- Quick retrieval from earlier learning (Recognise equivalent expressions). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which expression is equivalent to 3(x + 4)? (3x + 12 / 3x + 4 / 7x / 3x + 7) → 3x + 12Prompt: The number outside multiplies EVERY term inside the brackets.
- Which expression is equivalent to 5y + 8 + 5y? (11y + 8 / 10y + 8 / 25y + 8 / 18y) → 10y + 8Prompt: Like terms have exactly the same variable part.
- Are 4(x + 9) and 4x + 36 equivalent? (Hint: test x = 4.) (Yes / No) → YesPrompt: Equivalent expressions give the same value for EVERY x.
Hook · 5 min
- Show a "think of a number" puzzle and ask the class to work out the starting number.
- Share the objective: Expand brackets with positive terms. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Expand 3(x + 12).
- Step 1: 3 × x = 3x
- Step 2: 3 × 12 = 36
- Step 3: 3x + 36
- Answer: 3x+36
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Expand 3(x + 3). → 3x+9Prompt: Multiply each term in the brackets by the number outside.
- Expand 7(5x + 9). → 35x+63Prompt: Multiply both terms inside by the number outside.
You do: independent practice · 10 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 · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Expand 2(x + 12). → 2x+24Prompt: Multiply each term in the brackets by the number outside.
- Expand 7(4a + 4b). → 28a+28bPrompt: Multiply each term by the number outside.
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: Recognise equivalent 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