Math lesson plan · 1st grade (Year 2 in England) · 45 minutes
Story problems: taking away and taking apart (to 20)
Addition and subtraction
CCSS 1.OA.A.1England: Y1 Addition and subtraction
Objective and success criteria
Students will: Story problems: taking away and taking apart (to 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 within 20; Story problems: taking away (to 10)
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 within 20; Story problems: taking away (to 10)). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Hana had 3 beads. Hana gave 1 to Chloe. How many beads does Hana have left? → 2Prompt: Hana gives some away, so the amount gets smaller.
- There were 15 marbles. Then 2 were used. How many are left? → 13Prompt: Are we taking away or finding a difference? Both are subtraction.
- Hana had 10 marbles. Hana gave 8 to Zoe. How many marbles does Hana have left? → 2Prompt: Hana gives some away, so the amount gets smaller.
Hook · 5 min
- Give a real shopping total or a score difference and ask for a quick estimate first.
- Share the objective: Story problems: taking away and taking apart (to 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: Leo had 13 blocks. Leo gave 2 to Mateo. How many blocks does Leo have left?
- Step 1: 13 − 2 = 11
- Step 2: 11
- Answer: 11
- 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.
- Arjun had 20 pencils. Arjun gave 18 to Ethan. How many pencils does Arjun have left? → 2Prompt: Arjun gives some away, so the amount gets smaller.
- Luis has 11 crayons. 4 are in a bag and the rest are on the floor. How many crayons are on the floor? → 7Prompt: The whole is 11. One part is 4.
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.
- Fatima had 19 balls. Fatima gave 7 to Maya. How many balls does Fatima have left? → 12Prompt: Fatima gives some away, so the amount gets smaller.
- Zara has 14 beads. 6 are in a bag and the rest are on the floor. How many beads are on the floor? → 8Prompt: The whole is 14. One part is 6.
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 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-1.
Free lesson plan from eurekami.com/lesson-plan-builder