Find the factors, then count them
Make every factor of a number from its own disks, in order, then look for factor patterns.
Before this, try: Flash card practice: guess, test, self-assess
You need: A Prime Colours card, a blank card mat and coloured counters.
Players: 2 (one builds, one checks)
Goal: Find every factor of a number, smallest first.
Steps
- Choose a number, for example 18, and put its disks next to an empty frame.
- Start with the empty frame: that's 1. Say it out loud.
- Move disks into the frame to make the next biggest factor, and say it.
- Keep going, only using the disks that make your number: 1, 2, 3, 6, 9, 18.
- Your partner watches for any factor you miss.
- Record the number of factors using the factors barchart
Factors are combinations
Prime factors are the building blocks of the multiplicative world. Every factor of 18 is just a combination of the disks that make 18, so the question becomes: how many combinations of those disks are there?
Find the factor patterns
Count the factors of each number and place its card on the bar chart.
- What other numbers have the same pattern of factors as 18?
- Can you predict the number of factors from the colours?
- What kind of numbers have a prime number of factors?
- Under 100, which number of factors never appears?
Printables
- Factor bar chart PDF
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