Mathematics
Intermediate
50 mins
Teacher/Student led
Learning Goals
Learning Outcomes
Lesson Files
+80 XP
What you need:
IWB/Projector/Large Screen

Factors, Multiples, Prime and Composite Numbers

Explore factors and multiples using visual grids, then classify numbers as prime or composite based on how many factors they have. Build confidence in finding all factors by pairing them up systematically.

Teacher Class Feed

Load previous activity

    1 - Getting Started ~4 mins

    Key point

    Illustration for Getting StartedHere is a number: 12. Which whole numbers divide evenly into 12, with nothing left over?

    Put your hand up and call one out when you have it. And here is the harder part: how would we be sure we have found all of them, and not missed any?

    👇 Mark your steps as done as you complete them.

    +5 XP

    2 - Watch and Notice ~11 mins

    The interactive shows four different number grids: multiples, factors and primes. Look at how the squares are shaded on each one, and be ready to say what pattern you see and why some numbers are left out.

    👇 Mark your steps as done as you complete them.

    +10 XP

    3 - Try It Together ~11 mins

    Key point

    We work through these together on one grid, one at a time — the grid clears between each so we see one clean pattern each time: first the factors of 18, then the factors of 30, then the multiples of 4, and finally the multiples of 7. One pupil comes to the board to shade each one, and everyone else's job is to call out the factors and multiples aloud and agree or correct together. Notice how the factors sit in scattered pairs, while the multiples march along a steady step.

    Factors and multiples together

    +15 XP

    4 - List the Factors in Your Copy ~3 mins

    COPYBOOK MOMENT

    In your maths copy, do this:

    1. List the factors of 12, 18 and 24 on three rows, pairing them up as you go so you don't miss any.
    2. Underline any factor that shows up on all three rows — those are the common factors.

    We will work the common-factor step together first with these three numbers, so everyone sees how to spot and underline them, before you finish the lists in your own copy.

    If you finish early, try this too:

    1. On each row, circle the number itself (12, 18 or 24) — remember every number is a factor of itself.
    +10 XP

    5 - Class Challenge ~8 mins

    Key point

    Today's challenge bank builds up: shade all the multiples of 3, then of 4, then of 5, then of 7, then of 8, and finally of 12. Before each one, predict how the pattern will look — will the shaded cells be crowded or spread out?

    Shade the multiples

    +15 XP
    Pupil practice
    Module 2 · Operations and Computational Fluency Number
    Lesson 30 · Factors, Multiples, Prime and Composite Numbers
    Download Activity Book page (PDF)
    123learn · Online learning platform

    Unlock the full learning experience

    You're previewing this lesson. Get full access to this lesson and hundreds more — each one ready to teach, with interactive activities, printable resources and pupil progress tracking built in.

    Hundreds of curriculum-aligned lessons
    Interactive activities in every lesson
    Printable resources & progress tracking
    Get started
    Copyright Notice
    This lesson is copyright of Coding Ireland 2017 - 2025. Unauthorised use, copying or distribution is not allowed.
    🍪 Our website uses cookies to make your browsing experience better. By using our website you agree to our use of cookies. Learn more