Math lesson plan · 2nd grade (Year 3 in England) · 60 minutes
Add two-digit numbers by splitting into tens and ones
Addition and subtraction
CCSS 2.NBT.B.5CCSS 2.NBT.B.9England: Y2 Addition and subtractionEngland: Y3 Addition and subtraction
Objective and success criteria
Students will: Add two-digit numbers by splitting into tens and ones.
- 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 without 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 · 6 min
- Quick retrieval from earlier learning (Add two-digit numbers without regrouping). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Kofi has 53 beads. Mateo gives Kofi 14 more. How many beads does Kofi have now? → 67Prompt: Kofi gets more, so the amount grows.
- 42 + __ = 65 → 23Prompt: How many tens must be added? How many ones?
- There are 16 acorns on the table and 53 acorns in a box. How many acorns are there altogether? → 69Prompt: Altogether means put both groups together.
Hook · 6 min
- Give a real shopping total or a score difference and ask for a quick estimate first.
- Share the objective: Add two-digit numbers by splitting into tens and ones. Read the success criteria together.
I do: model it · 12 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: 45 + 46: add the tens. 40 + 40 = ?
- Step 1: 40 + 40 = 80
- Answer: 80
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 12 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- 17 + 45: add the tens. 10 + 40 = ? → 50Prompt: 1 ten + 4 tens
- Add by splitting: 19 + 16 = ? → 35Prompt: Split both numbers into tens and ones.
You do: independent practice · 17 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 · 7 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- 38 + 55: add the ones. 8 + 5 = ? → 13Prompt: Make a ten if you can.
- Add by splitting: 24 + 27 = ? → 51Prompt: Split both numbers into tens and ones.
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 without 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