Scholastic
Scholastic: Math Maven's Mysteries: The Bell Clapper Caper
Help the Math Maven get the kids out of school on time. Someone has stolen the bell's clapper and if the bell doesn't ring at 3:00, the school doors will not open! You have to figure out the last question to ask the number one suspect.
University of Cambridge
University of Cambridge: Nrich: Seven Pots of Plants
On this one page website sharpen your logic skills while working on this flower pot labels mix up challenge. The solution is available to double check your solution.
University of Cambridge
University of Cambridge: Nrich: Briefcase Lock
Use logic and reason to figure out what the correct combination of numbers are for the locked briefcase. At this one page website you can also check the solution.