Math lesson plan · 6th grade (Year 7 in England) · 45 minutes
Write inequalities for real-life limits
Algebra
CCSS 6.EE.B.8England: KS3 Algebra
Objective and success criteria
Students will: Write inequalities for real-life limits.
- 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: Inequalities: meaning and solutions
Leads to: Match inequalities and number-line graphs
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 (Inequalities: meaning and solutions). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which inequality matches? "The lift holds at most 13 people." (x is the amount) (x > 13 / x < 13 / x ≥ 13 / x ≤ 13) → x ≤ 13Prompt: 'At least' means that number or more.
- Which inequality matches? "You must be at least 12 years old to ride." (x is the amount) (x > 12 / x < 12 / x ≥ 12 / x ≤ 12) → x ≥ 12Prompt: 'At least' means that number or more.
- Which inequality matches? "You must be at least 5 years old to ride." (x is the amount) (x > 5 / x < 5 / x ≥ 5 / x ≤ 5) → x ≥ 5Prompt: 'At least' means that number or more.
Hook · 5 min
- Show a "think of a number" puzzle and ask the class to work out the starting number.
- Share the objective: Write inequalities for real-life limits. 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: Write an inequality: The speed limit is 88 km/h (s = speed). (Type ≤ as <= and ≥ as >= if you need to.)
- Step 1: s ≤ 88
- Answer: s ≤ 88
- 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.
- Write an inequality: Fewer than 20 people can be in the lift (p = people). (Type ≤ as <= and ≥ as >= if you need to.) → p < 20Prompt: “At least” means ≥; “at most” means ≤.
- Write as an inequality: x is greater than or equal to −1. → x ≥ −1Prompt: Start with x, then the sign, then the number.
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.
- Which inequality matches: The speed limit is 52 km/h (s = speed). (s ≥ 52 / s < 52 / s > 52 / s ≤ 52) → s ≤ 52Prompt: Is 52 itself allowed?
- Write an inequality: A phone needs at least 52% charge for an update (c = charge). (Type ≤ as <= and ≥ as >= if you need to.) → c ≥ 52Prompt: “At least” means ≥; “at most” means ≤.
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: Inequalities: meaning and solutions.
- 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
- Move on to: Match inequalities and number-line graphs.
- 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