Skip over navigation
Try plenty of examples :
Maybe start with other numbers and take multiples but continue dividing by 9.
There's Always One Isn't There
Age 14 to 16
Challenge Level 
Try plenty of examples :
Maybe start with other numbers and take multiples but continue dividing by 9.
Next use other numbers again, taking multiples of each as before but now divide by 7.
Then again use different numbers, take multiples and divide by 8 - be sure to include 12 as on of the numbers you try multiples of.
What happens?
Why?
You may also like
DOTS Division
Take any pair of two digit numbers x=ab and y=cd where, without loss of generality, ab > cd . Form two 4 digit numbers r=abcd and s=cdab and calculate: {r^2 - s^2} /{x^2 - y^2}.
