Math lesson plan · 1st grade (Year 2 in England) · 60 minutes
Fact families within 20
Addition and subtraction
CCSS 1.OA.B.4CCSS 1.OA.C.6England: Y1 Addition and subtractionEngland: Y2 Addition and subtraction
Objective and success criteria
Students will: Fact families 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: Subtract by thinking of an addition
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 (Subtract by thinking of an addition). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- 9 + 3 = 12. Use this to find 12 − 9. → 3Prompt: 9 and what make 12?
- To work out 12 − 4, think: 4 + __ = 12 → 8Prompt: Count up from 4 to 12.
- Which addition helps you work out 12 − 8? (4 + 12 = 16 / 8 + 4 = 12 / 12 + 8 = 20 / 8 + 8 = 16) → 8 + 4 = 12Prompt: The helpful addition uses the same three numbers.
Hook · 6 min
- Give a real shopping total or a score difference and ask for a quick estimate first.
- Share the objective: Fact families within 20. 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: 4 + 3 = 7 is in a fact family. Complete another fact: 3 + 4 = __
- Step 1: 3 + 4 = 7
- Answer: 7
- 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.
- 7 + 2 = 9 is in a fact family. Complete another fact: 9 − 2 = __ → 7Prompt: The family uses the numbers 7, 2 and 9.
- Which fact belongs to the same family as 8 + 4 = 12? (12 + 8 = 20 / 12 − 8 = 5 / 9 + 4 = 13 / 12 − 8 = 4) → 12 − 8 = 4Prompt: A family only uses 8, 4 and 12.
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.
- Which fact belongs to the same family as 7 + 8 = 15? (8 + 8 = 16 / 15 − 7 = 9 / 15 − 7 = 8 / 15 + 7 = 22) → 15 − 7 = 8Prompt: A family only uses 7, 8 and 15.
- 3 + 7 = 10 is in a fact family. Complete another fact: 10 − 3 = __ → 7Prompt: The family uses the numbers 3, 7 and 10.
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: Subtract by thinking of an addition.
- 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-1.
Free lesson plan from eurekami.com/lesson-plan-builder