Math lesson plan · 1st grade (Year 2 in England) · 45 minutes
Add three small numbers
Addition and subtraction
CCSS 1.OA.A.2CCSS 1.OA.B.3England: Y1 Addition and subtractionEngland: Y2 Addition and subtraction
Objective and success criteria
Students will: Add three small numbers.
- 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: Add within 20
Leads to: Story problems with three numbers
Materials: Base-ten blocks, Number lines, Hundred square, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Add within 20). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Ines has 5 shells. A friend gives Ines 3 more. How many shells does Ines have now? → 8Prompt: Do we join the groups or take away?
- 8 + 5 + 7 = ? → 20Prompt: You can add three numbers in any order.
- Hiro has 6 stickers. A friend gives Hiro 4 more. How many stickers does Hiro have now? → 10Prompt: Do we join the groups or take away?
Hook · 5 min
- Give a real shopping total or a score difference and ask for a quick estimate first.
- Share the objective: Add three small numbers. 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: 3 + 5 + 4 = ?
- Step 1: 3 + 5 = 8
- Step 2: 8 + 4 = 12
- Answer: 12
- 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.
- 2 + 3 + 6 = ? → 11Prompt: Add two of the numbers first.
- Look for two numbers that make 10, then add: 3 + 7 + 6 = ? → 16Prompt: Which two numbers make 10?
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.
- Look for two numbers that make 10, then add: 1 + 3 + 9 = ? → 13Prompt: Which two numbers make 10?
- 5 + 3 + 1 = ? → 9Prompt: Add two of the numbers first.
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: Add within 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 with three numbers.
- 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