### Pebbles

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?

### Counting Factors

Is there an efficient way to work out how many factors a large number has?

### Repeaters

Choose any 3 digits and make a 6 digit number by repeating the 3 digits in the same order (e.g. 594594). Explain why whatever digits you choose the number will always be divisible by 7, 11 and 13.

# Alison's Quilt

##### Age 11 to 14 Challenge Level:

Alison joins together nine squares with side lengths $1, 4, 7, 8, 9, 10, 14, 15$ and $18$ cm with no gaps and no overlaps, to form a rectangular quilt.

Can you find the dimensions of the finished quilt, and show how Alison fitted the squares together?

Alison wants to make a second quilt from ten squares with side lengths $3, 5, 6, 11, 17, 19, 22, 23, 24$ and $25$ cm.

Can you find the dimensions of this quilt?