### Where Can We Visit?

Charlie and Abi put a counter on 42. They wondered if they could visit all the other numbers on their 1-100 board, moving the counter using just these two operations: x2 and -5. What do you think?

### Babylon Numbers

Can you make a hypothesis to explain these ancient numbers?

### Ishango Bone

Can you decode the mysterious markings on this ancient bone tool?

# Gr8 Coach

##### Stage: 3 Challenge Level:
Imagine you are a rowing coach training a crew of eight for a race.

You must decide on the most effective training regime for your crew. How many minutes of circuit training should they do each day? How far should they run and how many miles of rowing each day would best prepare them?

Try out your initial ideas using the interactivity below.
How will you know that the schedule you have chosen will give the optimum performance from your crew?

What is the crew's optimal training regime? Please let us know how you reached your conclusions.

If you can see this message Flash may not be working in your browser
Please see http://nrich.maths.org/techhelp/#flash to enable it.