Stage: 2 Challenge Level: 
On a digital clock showing $24$-hour time, over a whole day, how many times does a $5$ appear?
Is it the same number for a $12$-hour clock over a whole day?
Click here for a poster of this resource.
Addition & subtraction. Factors and multiples. Visualising. Clock. Multiplication & division. Interactivities. Working systematically. Time. Investigations. Combinations.
Published October 1998,November 2008,December 2008.
Copyright © 2007. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project, which also includes the Plus and Motivate sites.
email: nrich@damtp.cam.ac.uk