Math lesson plan · 2nd grade (Year 3 in England) · 45 minutes
Add two-digit numbers without regrouping
Addition and subtraction
CCSS 2.NBT.B.5England: Y2 Addition and subtraction
Objective and success criteria
Students will: Add two-digit numbers without regrouping.
- 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 tens to a two-digit number; Add a one-digit number to a two-digit number (no new ten)
Leads to: Add two-digit numbers by splitting into tens and ones; Add three-digit numbers without regrouping
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 tens to a two-digit number; Add a one-digit number to a two-digit number (no new ten)). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
Hook · 5 min
- Give a real shopping total or a score difference and ask for a quick estimate first.
- Share the objective: Add two-digit numbers without regrouping. 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: There are 12 apples on the table and 46 apples in a box. How many apples are there altogether?
- Step 1: 12 + 46 = 58
- Step 2: 58
- Answer: 58
- 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.
- There are 18 marbles on the table and 61 marbles in a box. How many marbles are there altogether? → 79Prompt: Altogether means put both groups together.
- 52 + __ = 89 → 37Prompt: How many tens must be added? How many ones?
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.
- 13 + __ = 69 → 56Prompt: How many tens must be added? How many ones?
- Omar has 46 balls. Noah gives Omar 21 more. How many balls does Omar have now? → 67Prompt: Omar gets more, so the amount grows.
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 tens to a two-digit number.
- 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: Add two-digit numbers by splitting into tens and ones; Add three-digit numbers without regrouping.
- 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