We can arrange dots in a similar way to the 5 on a dice and they usually sit quite well into a rectangular shape. How many altogether in this 3 by 5? What happens for other sizes?
Age 7 to 11 Challenge Level
I have a square table-mat made from rope that spirals from the
centre. It is rather like this one:
The mat is a $14$ centimetre square. The rope is $2$ cm wide.
How many centimetres of rope will I need to make another mat
just like it?
How much rope would I need to make a $12$ cm square, or a $16$
Is there a quick way to work this out?
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.