Math lesson plan · 1st grade (Year 2 in England) · 45 minutes
Count backwards within 120
Number sense
CCSS 1.NBT.A.1England: Y1 Number and place value
Objective and success criteria
Students will: Count backwards within 120.
- 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: Count back from 10 and from 20; Count to 120
Leads to: the next skill in this area.
Materials: Place value chart, Base-ten blocks or a number line, Mini whiteboards and pens, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Count back from 10 and from 20; Count to 120). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Count back: 5, 4, 3, __ → 2Prompt: Counting back, each number is one less.
- A rocket countdown has a number missing: 10, 9, __, 7, 6 → 8Prompt: The numbers go down by one each time.
- Count back: 6, 5, 4, __ → 3Prompt: Counting back, each number is one less.
Hook · 5 min
- Show a number in the news or a price tag and ask what each digit is worth.
- Share the objective: Count backwards within 120. 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: Count back: 60, 59, 58, __
- Step 1: 58 − 1 = 57
- Step 2: 57
- Answer: 57
- 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.
- Count back: 26, 25, 24, __ → 23Prompt: Each number is one less than the one before.
- What number comes just before 90? (79 / 81 / 89 / 80) → 89Prompt: Just before means one less.
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.
- What number comes just before 30? (20 / 29 / 31 / 21) → 29Prompt: Just before means one less.
- Count back: 105, 104, 103, __ → 102Prompt: Each number is one less than the one before.
Watch out for
- Reading 1,045 as one thousand four hundred five: point to each place and say its value.
- Thinking a longer number is always bigger, even with decimals (0.45 vs 0.5).
Support and stretch
Support
- Review first: Count back from 10 and from 20.
- Use concrete materials: place value chart.
- 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