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...
Investigate how you can work out what day of the week your birthday will be on next year, and the year after...
We define $a\oplus b = ab + a + b $. If $3 \oplus 5= 2 \oplus x$, what is the value of $x$? If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.