You may also like

problem icon

Consecutive Numbers

An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.

problem icon

Calendar Capers

Choose any three by three square of dates on a calendar page...

problem icon

Days and Dates

Investigate how you can work out what day of the week your birthday will be on next year, and the year after...

Grid Without Lines

Stage: 3 Short Challenge Level: Challenge Level:1
At least one point must be removed from each of the three horizontal lines; so at least three need to be removed. However, removing the three points lying on either diagonal does what is required.

This problem is taken from the UKMT Mathematical Challenges.