Math lesson plan · 6th grade (Year 7 in England) · 45 minutes
Inequalities: meaning and solutions
Algebra
CCSS 6.EE.B.5CCSS 6.EE.B.8England: KS3 AlgebraEngland: GCSE Foundation Algebra
Objective and success criteria
Students will: Inequalities: meaning and solutions.
- 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: Negative numbers and absolute value; Write algebraic expressions
Leads to: Solve linear inequalities; Write inequalities for real-life limits; Solve one-step inequalities, including dividing by a negative
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 (Negative numbers and absolute value; Write algebraic expressions). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which expression means "10 less than n"? (10n / n − 10 / n + 10 / n/10) → n − 10Prompt: Translate the words in order, carefully.
- The temperature is 12 °C at noon and −7 °C at night. By how many degrees did it fall? → 19Prompt: Find the distance between the two numbers on the number line.
- Which expression means "9 times n"? (9 − n / n − 9 / n + 9 / 9n) → 9nPrompt: Translate the words in order, carefully.
Hook · 5 min
- Show a "think of a number" puzzle and ask the class to work out the starting number.
- Share the objective: Inequalities: meaning and solutions. 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: Which inequality matches? "You must be at least 12 years old to ride." (x is the amount)
- Step 1: x ≥ 12
- Answer: x ≥ 12
- 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.
- Which inequality matches? "The temperature stayed below 9 °C all day." (x is the amount) (x > 9 / x < 9 / x ≥ 9 / x ≤ 9) → x < 9Prompt: 'At least' means that number or more.
- Which inequality matches? "The temperature stayed below 10 °C all day." (x is the amount) (x > 10 / x < 10 / x ≥ 10 / x ≤ 10) → x < 10Prompt: 'At least' means that number or more.
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? "You must be at least 16 years old to ride." (x is the amount) (x > 16 / x < 16 / x ≥ 16 / x ≤ 16) → x ≥ 16Prompt: 'At least' means that number or more.
- Which inequality matches? "The temperature stayed below 9 °C all day." (x is the amount) (x > 9 / x < 9 / x ≥ 9 / x ≤ 9) → x < 9Prompt: 'At least' means that number or more.
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: Negative numbers and absolute value.
- 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: Solve linear inequalities; Write inequalities for real-life limits; Solve one-step inequalities, including dividing by a negative.
- 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