Copyright © University of Cambridge. All rights reserved.

'Reverse Subtraction' printed from

Show menu

In the subtraction sum on the right a, b and c are digits, and a is less than b.
What is the value of c?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.  

This problem is taken from the UKMT Mathematical Challenges.
View the archive of all weekly problems grouped by curriculum topic

View the previous week's solution
View the current weekly problem