You will learn
- Convert length.
- Convert mass.
- Convert capacity.
- Choose sensible units.
Version 0.2 · expanded edition · built from cited public sources Content is based on the official frameworks and sources listed under Sources and standards. No official endorsement is claimed. Written in the style of common primary school assessments. No exam result is promised.
Student lesson
- Kilo means 1,000; centi means one hundredth; milli means one thousandth.
- To a smaller unit, multiply.
- To a larger unit, divide.
- Choose a unit that fits the size.
Words to know
1,000 times.
One hundredth.
One thousandth.
Change units.
1. Discover: long road
A road is 3.5 km long. How many metres is that?
2. Understand: metric conversion
- 1 km = 1,000 m, so 3.5 km = 3,500 m.
- 250 cm ÷ 100 = 2.5 m.
- 4 kg × 1,000 = 4,000 g.
- 2.5 L × 1,000 = 2,500 mL, and 600 mm = 60 cm.
Idea 1: Length
2 km = 2 × 1,000 = 2,000 m. 250 cm ÷ 100 = 2.5 m. 600 mm ÷ 10 = 60 cm.
Idea 2: Mass and capacity
4 kg × 1,000 = 4,000 g. 2.5 L × 1,000 = 2,500 mL.
Idea 3: Check
3.5 km is 3,500 m.
Why multiply? Smaller units fit in greater numbers.
3. Worked examples
Example 1 (I show you): Length
2 km in m
- × 1,000.
Answer: 2,000 m
Example 2 (We do it together): Length
250 cm in m
- ÷ 100.
Answer: 2.5 m
Example 3 (You try): Capacity
2.5 L in mL
Show the steps and answer
- × 1,000.
Answer: 2,500 mL
Did you know?
The metric system is based on powers of 10.
Why this matters
Converting units lets us compare and measure accurately.
4. Explore: convert
You need paper.
- Find the factor.
- Multiply or divide.
- Move the point.
- Check sense.
Think about it: what did you notice?
3,500 m.
5. Practise
Say it in a sentence
Use these starters when you talk about the lesson. Say them out loud.
- 1 ___ = ___ ___.
- To change to a smaller unit I ___.
- To change to a larger unit I ___.
- So ___ = ___.
Guided practice
Question 1. 3.5 km in metres?
3,500 m.
Question 2. 250 cm in metres?
2.5 m.
Question 3. 4 kg in grams?
4,000 g.
Independent practice
Level 1: Start
- 2 km in m
- 250 cm in m
- 4 kg in g
- 2.5 L in mL
- 600 mm in cm
Level 2: Grow
- 5 km in m
- 3.2 m in cm
- 7,000 g in kg
Level 3: Stretch
- 0.75 km in m
- 1,500 m in km
- Ben says 600 mm = 6 cm. What is wrong?
Answers are in the answer key below. Try first, then check.
6. Apply: everyday mathematics
A road is 3.5 km. How many metres?
Show a sample answer
3,500 m.
Another one. A bottle holds 1.5 L. How many 250 mL glasses can it fill?
Show a sample answer
6
7. Common mistakes
Fix: Smaller unit means more of them.
Fix: Divide to go larger.
Fix: 1 km = 1,000 m.
8. Lesson summary and revision card
- I can convert length.
- I can convert mass.
- I can convert capacity.
- I can choose sensible units.
9. Check and master
Answer all 14 questions. You will see feedback after each one.
Your result appears here after you answer every question.
10. Key takeaways
- kilo = 1,000; centi = 1/100; milli = 1/1000.
- Multiply to a smaller unit.
- Divide to a larger unit.
11. Next lesson
Next lesson: Perimeter. Keep going with the next idea in this course.
Exam practice
These questions are written in the style of common school and international primary assessments. Try them on your own, without looking back. Then check your answers in the marking guide. The marks are shown in brackets.
- Convert 2 km to metres. [2 marks]
- Convert 250 cm to metres. [2 marks]
- Convert 4 kg to grams. [2 marks]
- Convert 2.5 L to millilitres. [2 marks]
- Ali says 600 mm is 6 cm. Is he right? Explain. [3 marks]
Total: 11 marks.
Marking guide and model answers
- 1 km = 1,000 m [1]; 2,000 m [1]
- 100 cm = 1 m [1]; 2.5 m [1]
- Multiply by 1,000 [1]; 4,000 g [1]
- Multiply by 1,000 [1]; 2,500 mL [1]
- No [1]. 10 mm = 1 cm, so divide by 10 [1]. 600 mm = 60 cm [1].
Score guide: 10 to 11 = secure. 7 to 9 = nearly there, revise the parts you missed. Under 7 = work through the lesson again with a grown-up.
Printable worksheet
- 2 km in m
- 250 cm in m
- 4 kg in g
- 2.5 L in mL
- 600 mm in cm
- 2 km in m
- 250 cm in m
- 4 kg in g
- 2.5 L in mL
- 600 mm in cm
Homework
Convert five measurements at home.
Answer key and marking scheme
| Question | Expected response | Marks |
|---|---|---|
| 2 km in m | 2,000 | 2 |
| 250 cm in m | 2.5 | 2 |
| 4 kg in g | 4,000 | 2 |
| 2.5 L in mL | 2,500 | 2 |
| 600 mm in cm | 60 | 2 |
| Total | 10 |
Practice answers: Worksheet: 1 2,000; 2 2.5; 3 4,000; 4 2,500; 5 60.
Quiz answers: 1 A, 2 B, 3 C, 4 A, 5 B, 6 A, 7 B, 8 C, 9 A, 10 B, 11 C, 12 A, Challenge 1 C, Challenge 2 C.
Extra worksheet answers (items 6 onward): 6 2,000 m; 7 2.5 m; 8 4,000 g; 9 2,500 mL; 10 60 cm.
Independent practice answers. Level 1: 1 2,000 m; 2 2.5 m; 3 4,000 g; 4 2,500 mL; 5 60 cm. Level 2: 1 5,000 m; 2 320 cm; 3 7 kg. Level 3: 1 750 m; 2 1.5 km; 3 10 mm = 1 cm, so 600 ÷ 10 = 60 cm..
Mastery and remediation
| Objective | Bronze (Developing) | Silver (Proficient) | Gold (Advanced) |
|---|---|---|---|
| O1 Convert length | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O2 Convert mass | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O3 Convert capacity | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
| O4 Choose sensible units | Shows this with help from an adult or a picture | Does this independently and explains how they know | Explains it clearly and uses it in a new situation |
Courseversity badge thresholds (overall quiz score): Gold = 90–100%; Silver = 80–89.9%; Bronze = 70–79.9%. A badge is never a full record of progress.
If a learner struggles
- Find the misconception: Dividing when changing to a smaller unit. Smaller unit means more of them.
- Explain another way: use real objects first, then pictures.
- Show a simpler example: cm and m.
- Guided practice: work through one example together and let the learner try the next one.
- Reassess: use the quiz again or the worksheet.
- Move on when the learner shows Silver-level evidence independently.
For parents and guardians
In this lesson your child converts metric units. You do not need to be good at mathematics to help.
- Read labels on food packs.
- Ask: bigger or smaller unit?
- Measure around the house.
- Ask “how do you know?” after each answer, and listen.
- Praise effort, not only right answers. Mistakes are how we learn.
- Ten to fifteen minutes a day is better than one long session.
Teacher package
1–5. Objectives, prerequisites, materials, preparation, duration
Lesson objectives. Learners will: convert length; convert mass; convert capacity; choose sensible units.
Prerequisite knowledge. Grade 5 measures.
Materials. Counters (stones, seeds or bottle tops), paper, pencils, board or chalkboard. Low-resource options: use stones, seeds, sticks, bottle tops or drawings in the sand or on the board instead of printed materials.
Preparation. Gather the counters and draw the example pictures on the board before the lesson.
Suggested duration. 45–60 minutes. It can be split into two shorter sessions.
6–9. Teaching procedure, explanation notes, guided and independent activities
Introduction (5 min). Start with the Discover situation and let learners suggest ideas before you teach.
Explanation (10 min). Teach the Understand section with real objects first, then pictures, then symbols and words.
Guided activity (10 min). You need paper. Learners follow the Explore steps in pairs.
Independent activity (10 min). Learners complete the independent practice and the worksheet.
Assessment and reflection (5 min). Ask each learner to say one thing they learned and how they know it.
Key questions. Bigger or smaller unit? Multiply or divide?
Teacher explanation notes. Use the concrete, pictorial, abstract order: real objects first, then pictures, then symbols and words. Return to real objects whenever a learner needs support.
10–12. Differentiation, formative assessment, common misconceptions
Support. Use real objects and work with a partner; say each step aloud together. Extension. Ask learners to make up their own example and explain it to a partner.
Formative assessment. Listen to learner explanations, ask “how do you know?”, and check the independent work.
Misconceptions. Dividing when changing to a smaller unit. Smaller unit means more of them.
13–15. Assessment questions, answer keys, marking scheme
Use the quiz and worksheet on this page. The 11-mark exam practice scheme, the 10-mark scheme and all answers are in the answer sections above. Re-check every answer and the marking scheme before publication.
16–19. Remediation, enrichment, homework, teacher reflection
Remediation. cm and m. Enrichment. Invite learners to find or create three more examples at home or in the classroom and explain them. Homework. See above.
Teacher reflection. After teaching, record: which concepts learners understood; which misconceptions occurred; which activities worked; which learners need more practice; and what to improve next time.
Sources and standards
This lesson is based on the sources below, and no official endorsement is claimed. Reference starting points named in the Courseversity standard: Common Core State Standards for Mathematics, Cambridge Primary and the IB Primary Years Programme. Where a standard code is named, it points to the official framework.
Official standards for this topic area. Common Core State Standards for Mathematics (official site): Grade 6 » Ratios & Proportional Relationships; Grade 6 » Geometry. These pages list the standards that cover this topic area; read them alongside the lesson.
Research used to shape this lesson. Common Core 5.MD.A.1 and 6.RP.A.3d; Cambridge Primary Mathematics Stage 6 (metric units). These sources informed the lesson.