Math lesson plan · 3rd grade (Year 4 in England) · 45 minutes
Grams and kilograms problems
Measurement
CCSS 3.MD.A.2England: Y3 Measurement
Objective and success criteria
Students will: Grams and kilograms problems.
- 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: Mass and capacity
Leads to: Convert kilograms and grams, litres and millilitres
Materials: Rulers, scales and measuring jugs, Clock faces, Conversion chart, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Mass and capacity). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Noah pours 597 ml of juice and 285 ml of water into a jug. How many millilitres are in the jug? → 882Prompt: Both amounts use the same unit, so you can add them.
- Felix puts 508 g of flour and 200 g of sugar in a bowl. What is the total mass in grams? → 708Prompt: Both amounts use the same unit, so you can add them.
- Jamal pours 309 ml of juice and 214 ml of water into a jug. How many millilitres are in the jug? → 523Prompt: Both amounts use the same unit, so you can add them.
Hook · 5 min
- Ask the class to estimate the length of the room or the weight of a bag before measuring it.
- Share the objective: Grams and kilograms problems. 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 bag of flour holds 1 kg. Yuki uses 550 g for a cake. How many grams are left?
- Step 1: 1 kg = 1000 g
- Step 2: 1000 − 550 = 450
- Step 3: 450 g
- Answer: 450
- 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 bag of flour holds 1 kg. Amara uses 200 g for a cake. How many grams are left? → 800Prompt: 1 kg is 1000 g.
- A melon weighs 400 g and each apple weighs 300 g. What do the melon and 4 apples weigh altogether, in grams? → 1600Prompt: First find the mass of 4 apples.
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.
- A bag of flour holds 2 kg. Diego uses 50 g for a cake. How many grams are left? → 1950Prompt: 1 kg is 1000 g.
- Would you measure the mass of a bicycle in grams or kilograms? (grams / kilograms) → kilogramsPrompt: Grams are for light things; kilograms are for heavier things.
Watch out for
- Measuring from the end of the ruler instead of zero.
- Converting units the wrong way (multiplying instead of dividing).
Support and stretch
Support
- Review first: Mass and capacity.
- Use concrete materials: rulers, scales and measuring jugs.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Convert kilograms and grams, litres and millilitres.
- 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-3.
Free lesson plan from eurekami.com/lesson-plan-builder