Math lesson plan · 8th grade (Year 9 in England) · 45 minutes
Compare real quantities in scientific notation
Number sense
CCSS 8.EE.A.3CCSS 8.EE.A.4England: KS3 NumberEngland: GCSE Foundation Number
Objective and success criteria
Students will: Compare real quantities in scientific notation.
- 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 and divide in scientific notation
Leads to: the next skill in this area.
Materials: Place value chart, Base-ten blocks or a number line, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Multiply and divide in scientific notation). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Work out (4 × 10⁶) × (1 × 10²). Give the answer in scientific notation. → 4 × 10⁸Prompt: Multiply the front numbers.
- Work out (9 × 10⁹) × (2 × 10⁶). Give the answer in scientific notation. → 1.8 × 10¹⁶Prompt: Multiply the front numbers and add the powers.
- Work out (8 × 10⁶) ÷ (2 × 10²). Give the answer in scientific notation. → 4 × 10⁴Prompt: Divide the front numbers.
Hook · 5 min
- Show a number in the news or a price tag and ask what each digit is worth.
- Share the objective: Compare real quantities in scientific notation. 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: A large hard drive holds 5 × 10⁵ bytes. A photo is 4 × 10³ bytes. How many photos fit on the drive?
- Step 1: 5 ÷ 4 = 1.25
- Step 2: 10⁵ ÷ 10³ = 10²
- Step 3: 125
- Answer: 125
- 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.
- A large hard drive holds 8 × 10⁶ bytes. A photo is 5 × 10³ bytes. How many photos fit on the drive? → 1600Prompt: Divide the drive size by the photo size.
- How many times heavier or larger is Jupiter's diameter (about 1.4 × 10⁵ km) than Earth's diameter (about 1.3 × 10⁴ km)? → 10.77Prompt: Divide the larger by the smaller.
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.
- How many times heavier or larger is the mass of the Earth (about 6 × 10²⁴ kg) than the mass of the Moon (about 7.5 × 10²² kg)? → 80Prompt: Divide the larger by the smaller.
- A large hard drive holds 6 × 10⁵ bytes. A photo is 4 × 10³ bytes. How many photos fit on the drive? → 150Prompt: Divide the drive size by the photo size.
Watch out for
- Reading 1,045 as one thousand four hundred five: point to each place and say its value.
- Thinking a longer number is always bigger, even with decimals (0.45 vs 0.5).
Support and stretch
Support
- Review first: Multiply and divide in scientific notation.
- Use concrete materials: place value chart.
- 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-8.
Free lesson plan from eurekami.com/lesson-plan-builder