Place four pebbles on the sand in the form of a square. Keep adding
as few pebbles as necessary to double the area. How many extra
pebbles are added each time?
Suppose we allow ourselves to use three numbers less than 10 and
multiply them together. How many different products can you find?
How do you know you've got them all?
Investigate the different shaped bracelets you could make from 18
different spherical beads. How do they compare if you use 24 beads?
There were many correct answers sent in
for this problem. As Primary Maths Club (International School of Toulouse) pointed out, it
helps if you start counting seconds from the first time the two
lights flashed together (at zero seconds).
Some people thought about a number line,
others looked for a number that both of the numbers of seconds (4
and 5) would divide into (common multiple). Here are two very well
Harriette, Caroline, Florence and
Rebecca from The Mount School, York:
Christina from Marlborough Primary