Free Grade 3 Units Lessons
Free Grade 3 lessons for Units: 12 real questions with a full answer key and worked solutions. Metric units change by powers of 10: 10 mm in a cm, 100 cm in a m, 1000 m in a km. Multiply to convert to a smaller unit, divide to convert to a bigger one.
Free
Foundation
15 min
24
Learning objectives
Every objective is checkable, and each one maps to an activity and an assessment.
- RememberIdentify units
Identify units accurately in a familiar context.
Assessed by: Exit ticket of four short items
- UnderstandExplain units
Explain units accurately in a familiar context.
Assessed by: Exit ticket of four short items
- ApplyCalculate units
Calculate units accurately in a familiar context.
Assessed by: Exit ticket of four short items
- AnalyseCompare units
Compare units accurately in a familiar context.
Assessed by: Exit ticket of four short items
Prerequisites
Close these gaps first — each has its own free lesson, worksheet and quiz.
How Units works
Metric units change by powers of 10: 10 mm in a cm, 100 cm in a m, 1000 m in a km. Multiply to convert to a smaller unit, divide to convert to a bigger one.
12 practice questions
Easy to hard, 24 marks in total. Try them first, then open the answers.
- 1.Convert 3 km to m.[1]
- 2.Convert 4 L to mL.[1]
- 3.Convert 3 m to cm.[1]
- 4.Convert 5 kg to g.[1]
- 5.Convert 4.4 cm to mm.[2]
- 6.Convert 4.8 L to mL.[2]
- 7.Convert 5.9 L to mL.[2]
- 8.Convert 5.4 L to mL.[2]
- 9.Convert 6.8 m to cm.[3]
- 10.Convert 1.1 km to m.[3]
- 11.Convert 5 km to m.[3]
- 12.Convert 5.1 cm to mm.[3]
Show answers and working
1. 3000 m
1 km = 1000 m. 3 × 1000 = 3000 m.
2. 4000 mL
1 L = 1000 mL. 4 × 1000 = 4000 mL.
3. 300 cm
1 m = 100 cm. 3 × 100 = 300 cm.
4. 5000 g
1 kg = 1000 g. 5 × 1000 = 5000 g.
5. 44 mm
1 cm = 10 mm. 4.4 × 10 = 44 mm.
6. 4800 mL
1 L = 1000 mL. 4.8 × 1000 = 4800 mL.
7. 5900 mL
1 L = 1000 mL. 5.9 × 1000 = 5900 mL.
8. 5400 mL
1 L = 1000 mL. 5.4 × 1000 = 5400 mL.
9. 680 cm
1 m = 100 cm. 6.8 × 100 = 680 cm.
10. 1100 m
1 km = 1000 m. 1.1 × 1000 = 1100 m.
11. 5000 m
1 km = 1000 m. 5 × 1000 = 5000 m.
12. 51 mm
1 cm = 10 mm. 5.1 × 10 = 51 mm.
Worked examples
Convert 9 cm to mm.
- 1 cm = 10 mm.
- 9 × 10 = 90 mm.
- Answer: 90 mm
Convert 1.6 m to cm.
- 1 m = 100 cm.
- 1.6 × 100 = 160 cm.
- Answer: 160 cm
Convert 8.2 m to cm.
- 1 m = 100 cm.
- 8.2 × 100 = 820 cm.
- Answer: 820 cm
Interactive practice
Free, no account required — answer on screen or print it.
Common mistakes
What learners typically get wrong, and how to fix it.
Divides when converting to a smaller unit.
Correction: Smaller units mean more of them — multiply.
Uses 100 for every conversion.
Correction: Learn which pairs use 10, 100 or 1000.
Teacher tips
- · Keep a conversion staircase on the wall.
Parent tips
- · Weigh fruit at the shop and convert kg to g.
Real-life applications
- · Cooking, measuring height, reading road signs.
Assessment objectives
How mastery is evidenced, and which standards it maps to.
Every free resource for Units
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Learn — Meet the idea.
Practice — Build fluency.
Revise — Keep it in memory.
Assess — Prove mastery.
Apply — Use it in context.
Teach — Deliver it to a class.
Frequently asked
- Is this Grade 3 Units lesson really free?
- Yes. Every lessons on FreeMathWorksheet is free to use, print and share — no account, no paywall and no watermark.
- What should a learner already know before this?
- Start with Geometry. Each one has its own free lesson, worksheet and quiz.
- How is the lesson sequenced?
- Recognition first, then understanding, application, reasoning and finally mastery — the same ladder used across every free resource on the platform.
- What comes next after Units?
- Move on to Time, Money, Number Sense, Algebra, which build directly on this idea.
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