Thursday, 19 March 2015

Am I a multiple of...?

How about trying this 'Mastery' activity in Maths....?
Did you know that if you double the last digit and subtract it from the number left by the remaining digits and if that equals 0 or is divisible by 7 then your starting number is a multiple of 7!  E.g. 672; 67 - 4 = 63 which is divisible by 7 so therefore 672 is a multiple of 7.  Challenge children to establish rules for finding multiples of numbers from 2 to 10.
A number is a multiple of:
2 if the last digit is even (0, 2, 4, 6, 8).
3 if the sum of the digits is divisible by 3.
4 if the last 2 digits are divisible by 4.
5 if the last digit is 0 or 5.
6 if the number is divisible by 2 (i.e. even) AND 3 (i.e. sum of digits is divisible by 3).
7 if you double the last digit and subtract it from the number made by the rest of the remaining digits and it equals 0 or is divisible by 7 e.g. 672; 67 - 4 = 63 which is divisible by 7.
8 if the last 3 digits are divisible by 8
9 if the sum of the digits is divisible by 9
10 if the number ends in a 0.

No comments:

Post a Comment