Divisibility, HCF, LCM and powers
Shade multiples on a hundred square to discover divisibility rules. Then common multiples and factors, square numbers and powers.
- UK: Year 5
- France: grade 5
- Germany: grade 5
- Iran: grade 4
- Afghanistan: grade 5
- Syria: grade 5
- Palestine: grade 4
- Ukraine: grade 5
- Russia: grade 5
Guide
This studio covers Years 5–6: multiples, factors, common multiples and factors, and square and cube numbers, with the divisibility tests.
The hundred square has two colours, red and blue. Choose a colour, then tap numbers. A number in both colours is shown half red, half blue. Tap two numbers and "keep jumping" shades the rest with the same gap.
The tests: a number divides by 2 if its last digit is even; by 5 if it ends in 0 or 5; by 10 if it ends in 0; by 3 or 9 if its digits add up to a multiple of 3 or 9.
The lowest common multiple (LCM) is the smallest number in both lists of multiples; the highest common factor (HCF) is the largest number that divides both numbers.
5 × 5 is "5 squared", written 5², and 4 × 4 × 4 is "4 cubed", 4³. In 4³ the 3 is the index (or exponent): how many 4s are multiplied.