Math lesson plan · 5th grade (Year 6 in England) · 30 minutes
Place the decimal point in a product
Decimals and percentages
CCSS 5.NBT.B.7England: Y6 Fractions (including decimals)
Objective and success criteria
Students will: Place the decimal point in a product.
- 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: Multiply 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 · 4 min
- Quick retrieval from earlier learning (Multiply decimals). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 7.8 × 4 = ? → 31.2Prompt: Multiply 78 × 4 as whole numbers first.
- 7.7 × 5.3 = ? → 40.81Prompt: Ignore the decimal points and multiply the whole numbers.
- Apples cost $3.99 per kilogram. How much do 3.5 kg cost? Round to the nearest cent (2 decimal places) and type the number only. → 13.97Prompt: Multiply the mass by the price per kilogram.
Hook · 3 min
- Show two prices or race times with decimals and ask which is bigger, then why.
- Share the objective: Place the decimal point in a product. Read the success criteria together.
I do: model it · 7 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: 27 × 74 = 1998. Use this to find 0.27 × 74.
- Step 1: 2 decimal places in total
- Step 2: 0.27 × 74 = 19.98
- Answer: 19.98
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 6 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- 29 × 15 = 435. Use this to find 0.29 × 15. → 4.35Prompt: Count the decimal places in both numbers.
- 69 × 35 = 2415. Use this to find 0.69 × 35. → 24.15Prompt: Count the decimal places in both numbers.
You do: independent practice · 7 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 6 questions are on the student sheet below, with answers in the key.
Exit ticket · 3 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- 85 × 64 = 5440. Use this to find 8.5 × 64. → 544Prompt: Count the decimal places in both numbers.
- 11 × 22 = 242. Use this to find 0.11 × 22. → 2.42Prompt: Count the decimal places in both numbers.
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: Multiply 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