### Times

Which times on a digital clock have a line of symmetry? Which look the same upside-down? You might like to try this investigation and find out!

### Clock Hands

This investigation explores using different shapes as the hands of the clock. What things occur as the the hands move.

### Ten Green Bottles

Do you know the rhyme about ten green bottles hanging on a wall? If the first bottle fell at ten past five and the others fell down at 5 minute intervals, what time would the last bottle fall down?

# Take the Right Angle

##### Stage: 2 Challenge Level:

Abby, Antony, James and Peter from Gateway school in Carterton wrote to say:

We found 22 right angles in 12 hours. All the right angles are listed below:
12:16 12:49 1:22 1:54 2:27 3:00 3:33 4:05 4:39 5:11 5:44 6:16 6:49 7:22 7:54 8:27 9:00 9:33 10:05 10:39 11:11 11:44.

One of these is a minute out according to the NRICH clock. Can you find which one?

William and Alex at Maadi British International School, Cairo used a wrist watch to work out the problem and agreed there were 22 right angles, so did Eliza and Milli from St Hilda's School.