An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.
Choose any three by three square of dates on a calendar page...
Can you make a tetrahedron whose faces all have the same perimeter?
How shall we start to make some progress with this challenge ?
Can you generalise your results somehow?
What is the same and what is different about the solution if the $10$ is changed to another number?