Math lesson plan · 5th grade (Year 6 in England) · 45 minutes
Subtract a decimal from a whole number
Decimals and percentages
CCSS 5.NBT.B.7England: Y5 Fractions (including decimals)
Objective and success criteria
Students will: Subtract a decimal from a whole number.
- 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: Add and subtract decimals
Leads to: the next skill in this area.
Materials: Place value chart with tenths and hundredths, Hundred squares, Number lines, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Add and subtract decimals). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 62 + 89.33 = ? → 151.33Prompt: Line up the decimal points.
- 5.78 − 5.5 = ? → 0.28Prompt: Line up the decimal points and fill gaps with zeros.
- 83.2 + 37.12 = ? → 120.32Prompt: Line up the decimal points.
Hook · 5 min
- Show two prices or race times with decimals and ask which is bigger, then why.
- Share the objective: Subtract a decimal from a whole number. 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: 2 − 1.42 = ?
- Step 1: 2.00 − 1.42 = 0.58
- Answer: 0.58
- 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.
- 18 − 5.97 = ? → 12.03Prompt: Write 18 as 18.00.
- Ava pays for a snack costing $11.50 with a $20 note. How much change does Ava get? → 8.5Prompt: Change = money given − price.
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.
- Ines pays for a snack costing $0.65 with a $1 coin. How much change does Ines get? → 0.35Prompt: Change = money given − price.
- 19 − 6.46 = ? → 12.54Prompt: Write 19 as 19.00.
Watch out for
- Thinking 0.45 is bigger than 0.5 because 45 is bigger than 5.
- Moving the digits the wrong way when multiplying or dividing by 10.
Support and stretch
Support
- Review first: Add and subtract decimals.
- Use concrete materials: place value chart with tenths and hundredths.
- 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-5.
Free lesson plan from eurekami.com/lesson-plan-builder