Math lesson plan · 1st grade (Year 2 in England) · 45 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 · 5 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.
- 7 + 9 = 16. Use this to find 16 − 7. → 9Prompt: 7 and what make 16?
- To work out 10 − 7, think: 7 + __ = 10 → 3Prompt: Count up from 7 to 10.
- Which addition helps you work out 17 − 8? (8 + 8 = 16 / 8 + 9 = 17 / 17 + 8 = 25 / 9 + 17 = 26) → 8 + 9 = 17Prompt: The helpful addition uses the same three numbers.
Hook · 5 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 · 10 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 · 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.
- 5 + 3 = 8 is in a fact family. Complete another fact: 8 − 3 = __ → 5Prompt: The family uses the numbers 5, 3 and 8.
- Which fact belongs to the same family as 9 + 2 = 11? (11 + 9 = 20 / 11 − 9 = 3 / 10 + 2 = 12 / 11 − 9 = 2) → 11 − 9 = 2Prompt: A family only uses 9, 2 and 11.
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.
- Which fact belongs to the same family as 3 + 5 = 8? (8 + 3 = 11 / 8 − 3 = 6 / 8 − 3 = 5 / 4 + 5 = 9) → 8 − 3 = 5Prompt: A family only uses 3, 5 and 8.
- 8 + 10 = 18 is in a fact family. Complete another fact: 18 − 8 = __ → 10Prompt: The family uses the numbers 8, 10 and 18.
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