Place value and divisibility

Recognise the model, justify the rule and solve independently.

Write a three-digit number with digits $a,b,c$ as $100a+10b+c$, where $a\ne 0$.

Use prime factorisation to compare divisibility and to find a greatest common divisor or a least common multiple.

Use parity to decide whether a sum or a sequence of moves can reach a given value.

Count the trailing zeros of a product by counting its factors of 2 and of 5 and taking the smaller count.