Work mathematically with rates to calculate an escape given increasingly difficult timings.

Work mathematically with rates to calculate an escape given increasingly difficult timings.

The Rate Escape

Can you navigate the deadly rings?

Watch the clock at the top right while the rings turn.
You can only launch at full turn of the clock (i.e. one *clock cycle*),
but will you make it through the rings?
The merest touch and your ship will explode!
Study the rotation rates below and calculate how long you should wait before blasting off to safety.
A perfect score is 100 — see how you go.

Ring rotation rates in degrees per clock cycle:

Launch every:

To complete the game, students must be able to convert the rotation rate given for each ring into a number of complete clock cycles before it is again aligned to the starting point (since that is the only point at which the ship can be launched). Because the game starts with a single ring, the basic calculation can be learned before there is any need to combine calculations and find a common multiple. More difficult rates are held back until the later rings.

(Shift-start will go straight to the last level)

Star image courtesy Pauline Moss.