You may also like

problem icon

Exploring Wild & Wonderful Number Patterns

EWWNP means Exploring Wild and Wonderful Number Patterns Created by Yourself! Investigate what happens if we create number patterns using some simple rules.

problem icon

I'm Eight

Find a great variety of ways of asking questions which make 8.

problem icon

Sending Cards

This challenge asks you to investigate the total number of cards that would be sent if four children send one to all three others. How many would be sent if there were five children? Six?

Penta Post

Stage: 2 Challenge Level: Challenge Level:1

Martha from Tattingstone School sent us a very clearly answer to the first part:

parcel would cost £3.20 so need three £1 stamps and two 10p stamps

Martha goes on to give the solution for the second part too: package costs 84p so for as few stamps as possible need two 37p and one 10p

Caroline, also from Tattingstone, has answered the third part of the problem: 44p can't be made

Well done Caroline - although perhaps it would have been better to write 3 x 4, not 4 x 3. Back to Martha for part four: 3 combinations: three 19p stamps; two 10p and a 37p or three 10p and a 27p

Finally, Caroline has answered the last part for us: up to 150g first class (costing 57p) and up to 200g second class (costing 54p)

Excellent answers both of you! Very well done.


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 - 2017. University of Cambridge. All rights reserved.
NRICH is part of the family of activities in the Millennium Mathematics Project.