Our dinosaur twins really know their doubles: how many doubles can be completed in just 40 seconds?
Double multiples of 5 as fast as possible. If the number has 5 in the units I double the tens and add 10!
When two numbers are consecutive it is often easier to add them by doubling and adjusting by 1.
Click on two dragons which have the same hidden totals to make them disappear.
Use the arrow keys to doge the blue balls. Ten sets of doubling questions to answer to complete the game successfully.