Highest Common Factor Domino Puzzle
With pupils on the lower end of the attainment spectrum I like to teach calculation of the highest common factor of a pair of numbers by the method of writing out the factors of each number, highlighting the common ones and then choosing the highest. I find this more successful than teaching them to use prime factorisation. Whilst this has the disadvatange of not being suitable for large numbers, I’ve yet to see a GCSE question that asks for HCF of two numbers that are too large to use the simpler method.
To add a nice change from simple ’10 questions’ worksheets I decided to put together the domino puzzle below based on finding HCF for relatively small numbers for one of my year 10 groups. This was made on the excellent Tarsia software that is available for free download.