Math lesson plan · 2nd grade (Year 3 in England) · 45 minutes
Quick addition and subtraction facts within 20
Addition and subtraction
CCSS 2.OA.B.2England: Y2 Addition and subtraction
Objective and success criteria
Students will: Quick addition and subtraction facts within 20.
- 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; Subtract within 20
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 · 5 min
- Quick retrieval from earlier learning (Add within 20; Subtract within 20). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- There are 5 crayons in a box and 8 on the table. How many crayons are there in all? → 13Prompt: Do we join the groups or take away?
- Maya collected 6 apples in the morning and 5 in the afternoon. How many is that altogether? → 11Prompt: Do we join the groups or take away?
- Grace collected 9 crayons in the morning and 4 in the afternoon. How many is that altogether? → 13Prompt: 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: Quick addition and subtraction facts within 20. 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: 8 + 9 = ?
- Step 1: 8 + 9 = 17
- Answer: 17
- 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.
- 6 + 7 = ? → 13Prompt: Is it a double or near double?
- 7 − 3 = ? → 4Prompt: Think: 3 + ? = 7
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.
- 11 − 7 = ? → 4Prompt: Think: 7 + ? = 11
- 7 − __ = 2 → 5Prompt: Which fact family does this belong to?
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
- 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