Math lesson plan · 1st grade (Year 2 in England) · 30 minutes
Story problems: find the missing change
Addition and subtraction
CCSS 1.OA.A.1CCSS 1.OA.D.8England: Y1 Addition and subtractionEngland: Y2 Addition and subtraction
Objective and success criteria
Students will: Story problems: find the missing change.
- 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: Story problems: adding on and putting together (to 20); Subtract by thinking of an addition
Leads to: Story problems: work out the starting amount
Materials: Base-ten blocks, Number lines, Hundred square, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 4 min
- Quick retrieval from earlier learning (Story problems: adding on and putting together (to 20); Subtract by thinking of an addition). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Noah has 7 birds. Arjun gives Noah 4 more. How many birds does Noah have now? → 11Prompt: Noah gets more, so the amount grows.
- There are 6 marbles on the table and 7 marbles in a box. How many marbles are there altogether? → 13Prompt: Altogether means put both groups together.
- 9 + 6 = 15. Use this to find 15 − 9. → 6Prompt: 9 and what make 15?
Hook · 3 min
- Give a real shopping total or a score difference and ask for a quick estimate first.
- Share the objective: Story problems: find the missing change. 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: Zoe had 8 flowers. Arjun gave Zoe some more. Now Zoe has 13. How many flowers did Arjun give?
- Step 1: 8 + 5 = 13
- Step 2: 5
- Answer: 5
- 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.
- Ava had 8 ducks. Priya gave Ava some more. Now Ava has 16. How many ducks did Priya give? → 8Prompt: 8 + ? = 16
- Mei had 20 shells. Mei gave some to Hana. Now Mei has 5 left. How many shells did Mei give away? → 15Prompt: Mei started with 20 and ended with 5.
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.
- Maya had some pencils. Then Maya got 8 more. Now Maya has 14. How many pencils did Maya have at the start? → 6Prompt: ? + 8 = 14
- Felix had 7 toy cars. Leo gave Felix some more. Now Felix has 12. How many toy cars did Leo give? → 5Prompt: 7 + ? = 12
Watch out for
- Subtracting the smaller digit from the bigger one in every column (52 − 17 = 45).
- Forgetting to add the regrouped (carried) ten.
Support and stretch
Support
- Review first: Story problems: adding on and putting together (to 20).
- Use concrete materials: base-ten blocks.
- 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: Story problems: work out the starting amount.
- 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-1.
Free lesson plan from eurekami.com/lesson-plan-builder