You may also like

problem icon

Skeleton

Amazing as it may seem the three fives remaining in the following `skeleton' are sufficient to reconstruct the entire long division sum.

problem icon

Alphabet Soup

This challenge is to make up YOUR OWN alphanumeric. Each letter represents a digit and where the same letter appears more than once it must represent the same digit each time.

problem icon

Medal Muddle

Countries from across the world competed in a sports tournament. Can you devise an efficient strategy to work out the order in which they finished?

Long Multiplication

Stage: 3 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

A 3 digit number is multiplied by a 2 digit number and the calculation is written out as shown below.
Each star like this stands for one digit.

Apart from the zero shown the only digits which occur are 2, 3, 5 and 7. This is sufficient information to complete the whole multiplication.

        

This is sufficient information to complete the whole multiplication sum.
        

You might find this sheet useful for working on the problem,
  
         
         
 
         

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.