Can you explain why every year must contain at least one Friday the thirteenth?
What is the greatest number of Friday the thirteenths that can fall in one year?
The NRICH website publishes free mathematics resources designed to challenge, engage and develop the mathematical thinking of students aged 5 to 19. NRICH also offers support for teachers by publishing Teachers’ Resources for use in the classroom.
This task can be found at: https://nrich.maths.org/610