RIC-0563 Developing algebraic thinking

DIVISIBILITY RULES
Teachers notes
Divisibility
rules 15
Divisibility rules 15
has all 3-digit numbers. Here is a list of possible
steps to solve this task.
• For 9 6 to be divisible by 4 and 9, the only choice of a digit in the
tens place is 3.
• For 7 to be divisible by 2 and 5, the only choice of a digit in the
ones place is 0.
• For 9 to be divisible by 3 and 5, the only choice of a digit in the
ones place is 5.
• For 64 to be divisible by 3 and 4, the only choice of a digit in the
ones place is 8.
• For 0 to be divisible by 2 and 9, the only choice of a digit in the
ones place is 2, and therefore, a 7 in the hundreds place.
• Now, for 3 to be divisible by 2 and 3, the only choice of a digit in
the ones place is 6, and therefore, the tens digit is 9.
• For 9 , the tens digit is 1 or 4, and for 7 , the hundreds digit
is 4 or 1.
R.I.C. Publications ® www.ricgroup.com.au DEVELOPING ALGEBRAIC THINKING 49
ISBN 978-1-74126-088-5