Filling the Gap from 1 to 70 | Primary 1 Second Term Maths Lesson Note

Filling the Gap from 1 to 70 | Primary 1 Second Term Maths Lesson Note

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Filling the Gap from 1 to 70 – Primary 1 Maths Lesson Note (2nd Term)

Lesson Note: Filling the Gap from 1 to 70

Subject: Mathematics

Class: Primary 1

Term: Second Term

Week: 1

Age: 5–6 years

Topic: Filling the Gap (1–70)

Sub-topic: Completing Missing Numbers

Duration: 40 Minutes

Behavioural Objectives

By the end of the lesson, pupils should be able to:

  1. Count numbers correctly from 1 to 70.
  2. Identify missing numbers in a number sequence.
  3. Fill in gaps between numbers 1 to 70 accurately.
  4. State what comes before, between, and after a given number.
  5. Arrange numbers in correct order (ascending and descending).

Keywords and Meanings

  1. Number: A symbol used to show quantity or position (1, 2, 3…).
  2. Count: Saying numbers in order (1, 2, 3…).
  3. Before: The number that comes earlier (e.g., before 5 is 4).
  4. After: The number that comes next (e.g., after 9 is 10).
  5. Between: The number that lies in the middle (e.g., between 2 and 4 is 3).
  6. Missing: Something that is not present or left out.
  7. Sequence: Numbers arranged in a specific order.
  8. Arrange: To put in proper order.
  9. Gap: The space where a number is missing.
  10. Order: A proper way of arranging numbers from small to big or big to small.

Set Induction (Attention-Grabber Story)

The teacher begins with a playful story:

“One bright morning, Chika and Musa were helping their teacher count pencils in class. They counted — 1, 2, 3, 4… suddenly they skipped some numbers! The teacher smiled and said, ‘Hmm… you left some gaps! Let’s find which numbers are missing.’ The pupils laughed and started counting again carefully — this time filling all the gaps!”

The teacher then asks:

“Children, can you help Chika and Musa fill the missing numbers from 1 to 70?”

This creates curiosity and connects learners emotionally to the topic.

Entry Behaviour

Pupils have already learned how to count and write numbers from 1 to 50 in their previous term.

Learning Resources and Materials

  • Number chart (1–100)
  • Flashcards with missing numbers
  • Counting sticks or bottle caps
  • Writing slates and markers
  • Board illustrations

Building Background / Connection to Prior Knowledge

Ask pupils to count from 1 to 50 aloud. Then ask questions like:

  • What comes after 10?
  • What comes before 20?
  • If I say 34, what number is next?

This links their old knowledge to the new topic.

Embedded Core Skills

  • Critical Thinking: Identifying missing numbers.
  • Communication: Saying numbers aloud clearly.
  • Collaboration: Working in pairs or small groups.
  • Creativity: Using local items for counting.
  • Digital Literacy: Viewing digital number charts on the smartboard or phone.

Learning Materials

  • Real objects for counting (bottle tops, sticks)
  • Wall charts
  • Worksheets with number gaps
  • Number line strip

Reference Books

  • Lagos State Unified Scheme of Work for Mathematics (Primary 1)
  • New Method Primary Mathematics Book 1
  • Universal Basic Education Curriculum (UBE)

Instructional Materials

  • Number chart (1–70)
  • Flashcards showing missing numbers
  • Writing board and marker
  • Worksheet on filling the gaps

CONTENT DEVELOPMENT

Meaning and Explanation of the Topic

“Filling the Gap” means completing a number sequence by putting in the missing numbers.
When we count from 1 to 70, sometimes some numbers are left out. We must find and fill them correctly.

Examples (1–10)

  1. 1, 2, ___, 4 → Missing number is 3
  2. 5, 6, ___, 8 → Missing number is 7
  3. 9, ___, 11, 12 → Missing number is 10
  4. 13, ___, 15 → Missing number is 14
  5. 18, 19, ___, 21 → Missing number is 20
  6. 29, 30, ___, 32 → Missing number is 31
  7. ___, 41, 42 → Missing number is 40
  8. 65, ___, 67 → Missing number is 66
  9. ___, 50, 51 → Missing number is 49
  10. 68, ___, 70 → Missing number is 69

In-depth Explanation with 5 Examples Each

1. Counting Numbers:
Counting means saying numbers in order.
Examples:
1–10, 11–20, 21–30, 31–40, 41–70

2. Missing Numbers:
A missing number is a number left out in a pattern.
Examples:
(a) 1, ___, 3 → Missing 2
(b) 10, ___, 12 → Missing 11
(c) ___, 22, 23 → Missing 21
(d) 40, ___, 42 → Missing 41
(e) 68, ___, 70 → Missing 69

3. Number Before:
This means the number that comes first.
Examples:
Before 5 is 4.
Before 21 is 20.
Before 34 is 33.
Before 67 is 66.
Before 12 is 11.

4. Number After:
This means the number that comes next.
Examples:
After 4 is 5.
After 11 is 12.
After 29 is 30.
After 59 is 60.
After 69 is 70.

5. Number Between:
The number that lies in the middle of two numbers.
Examples:
Between 2 and 4 is 3.
Between 9 and 11 is 10.
Between 49 and 51 is 50.
Between 19 and 21 is 20.
Between 34 and 36 is 35.

Presentation

Step 1: Revision of Previous Lesson

The teacher revises counting numbers from 1 to 50.

Step 2: Introduction of the New Topic

Teacher introduces “Filling the Gap from 1 to 70” by writing examples on the board.

Step 3: Teacher’s Activities

  1. Write number sequences with gaps on the board.
  2. Ask pupils to fill in the missing numbers.
  3. Display flashcards for class practice.
  4. Guide pupils to count in ascending and descending order.
  5. Correct pupils and reinforce understanding.

Step 4: Learners’ Activities

  1. Count numbers aloud with the teacher.
  2. Fill in the missing numbers on the board or chart.
  3. Work in pairs to complete worksheets.
  4. Respond to teacher’s oral questions.

Class Activity Discussion (FAQs)

  1. Q: What is a missing number?
    A: A number that is left out in a sequence.
  2. Q: What number comes after 9?
    A: 10
  3. Q: What number comes before 13?
    A: 12
  4. Q: What comes between 17 and 19?
    A: 18
  5. Q: What number comes after 59?
    A: 60
  6. Q: What number comes before 40?
    A: 39
  7. Q: If 65, ___, 67, what is missing?
    A: 66
  8. Q: Between 28 and 30 is what?
    A: 29
  9. Q: What number is missing in 44, ___, 46?
    A: 45
  10. Q: What comes before 1?
    A: Zero (0)

Evaluation Questions

A. Fill in the Blank (Choose a, b, c, or d)

  1. 1, 2, ___, 4
    (a) 3 (b) 5 (c) 6 (d) 7
  2. 9, 10, ___, 12
    (a) 11 (b) 9 (c) 13 (d) 8
  3. ___, 20, 21
    (a) 18 (b) 19 (c) 22 (d) 23
  4. 31, ___, 33
    (a) 30 (b) 32 (c) 34 (d) 35
  5. ___, 50, 51
    (a) 48 (b) 49 (c) 52 (d) 53
  6. 64, 65, ___
    (a) 66 (b) 63 (c) 67 (d) 68
  7. 46, ___, 48
    (a) 45 (b) 49 (c) 47 (d) 44
  8. 25, ___, 27
    (a) 24 (b) 28 (c) 26 (d) 23
  9. 67, ___, 69
    (a) 66 (b) 68 (c) 70 (d) 65
  10. ___, 14, 15
    (a) 16 (b) 13 (c) 12 (d) 11

B. Short Answer Questions

  1. What number comes after 10?
  2. What number comes before 7?
  3. What number is between 19 and 21?
  4. Fill in: 44, ___, 46.
  5. What number comes after 59?
  6. What comes before 12?
  7. Fill in: 30, ___, 32.
  8. What is the missing number in 65, ___, 67?
  9. What number comes before 70?
  10. Fill in: 9, ___, 11.

Assessment

Teacher gives short exercises orally and on paper.

Conclusion

The teacher revises the topic by asking pupils to count from 1–70 aloud.
Walks around to check their work, marks their answers, and gives positive feedback with a smile or star sticker.

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