Problem
First name
Seth Wilkinson
School
Middleton Tyas CofE Primary School
Country
Age
10
Having tried this activity a few times, I found the following method easiest:
First, I divided by 10. The answer given was a remainder of 9 so I knew that the number ends in 9 i.e: 19,29,39,49,59,69,79,89,99.
Next, I worked out which numbers go into the numbers above i.e: 3(39,99), 7(49) and 9(99). I found using the larger numbers helped so I divided by 9, this gave me a remainder of 0. The answer in this instance has to be 99!