Correct solutions were sent in by Jade and Sarah from Willaston Primary School, Isle Of Man and Gemma from Annesley College, South Australia
Annabelle also from Annesley College, South Australia explained the process:
"We started with the 90's because it was less then 100 but still close to the numbers in the box. We tried all different starting points and ended up with 99. To see if 99 worked we took 99 from 127 which gave us 28. Then we took 28 from 201 which gave us 173."