Math lesson plan · 2nd grade (Year 3 in England) · 30 minutes
Add three or four two-digit numbers
Addition and subtraction
CCSS 2.NBT.B.6England: Y2 Addition and subtractionEngland: Y3 Addition and subtraction
Objective and success criteria
Students will: Add three or four two-digit 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 two-digit numbers with regrouping
Leads to: the next skill in this area.
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 (Add two-digit numbers with regrouping). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Fatima has 39 balls. A friend gives Fatima 23 more. How many balls does Fatima have now? → 62Prompt: Add the tens, then add the ones.
- 28 + 11 + 11 = ? → 50Prompt: Add two numbers first, then add the third.
- There are 33 crayons in a box and 37 on the table. How many crayons are there in all? → 70Prompt: Add the tens, then add the ones.
Hook · 3 min
- Give a real shopping total or a score difference and ask for a quick estimate first.
- Share the objective: Add three or four two-digit numbers. 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: 14 + 28 + 25 = ?
- Step 1: Tens: 10 + 20 + 20 = 50
- Step 2: Ones: 4 + 8 + 5 = 17
- Step 3: 67
- Answer: 67
- 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.
- 35 + 24 + 21 = ? → 80Prompt: Add the tens together, then the ones together.
- Ines walked 19 minutes on Monday, 10 on Tuesday, 12 on Wednesday and 11 on Thursday. How many minutes is that in total? → 52Prompt: Add all four numbers.
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.
- 12 + 25 + 13 = ? → 50Prompt: Add the tens together, then the ones together.
- Hana walked 20 minutes on Monday, 11 on Tuesday, 17 on Wednesday and 12 on Thursday. How many minutes is that in total? → 60Prompt: Add all four numbers.
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 two-digit numbers with regrouping.
- 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
- 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-2.
Free lesson plan from eurekami.com/lesson-plan-builder