You may also like

problem icon

GOT IT Now

For this challenge, you'll need to play Got It! Can you explain the strategy for winning this game with any target?

problem icon

Is There a Theorem?

Draw a square. A second square of the same size slides around the first always maintaining contact and keeping the same orientation. How far does the dot travel?

problem icon

Reverse to Order

Take any two digit number, for example 58. What do you have to do to reverse the order of the digits? Can you find a rule for reversing the order of digits for any two digit number?

Chocolate Maths

Stage: 3 Challenge Level: Challenge Level:1

Thank you to Gareth Matthews, Llantwit Major Comprehensive School for this solution. Jenny Cook, age 15, The Mount School York, Andrei Lazanu, age 12, School 205, Bucharest, Romania and Clement Goh, age 13, from River Valley High School, Singapore all sent good solutions.

I used algebra to get my answer.

The problem The solution My calculation
First of all, pick the number of times a week that you eat chocolate. A 7
Multiply this number by 2 (just to be bold). 2A 14
Add 5 (for Sunday). 2A+5 19
Multiply it by 50. 100A+250
This multiplies the original number by 100 and adds 250		 950
Add 1750, then the last two digits of the year you last had a birthday. 100A+2000+ab
 2709
Now subtract the four digit year that you were born (if you remember). 100A +2000+ab-cdef
Subtracting the year i was born (cdef) from the year I last had a birthday (20ab) gives my age. 100A puts the number A in the hundreds place.		 714

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice. More information on many of our other activities can be found here.
Copyright © 1997 - 2012. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project.