Mental Math

20 + 0.6 + 0.02

I have a litre bottle of coke. I drink 650ml. How much is left?

Which two numbers have a sum of 15 and a product of 36?

(a)  

A kid's skipping rope is 210cm long. How many rope could I cut from a 10-metres long piece of rope?

How many thirds make 5?

Find the value of (x - 6)/3, if x = 21.

In a group of children, 3/5 like to play tennis. If there are 25 children, how many do not like to play tennis?

Which is the smallest?

0.37, 0.194, 0.6, 0.473, 0.29

(a)  

A rectangular swimming pool measures  $5\frac{1}{2}$  metres by  $3\frac{1}{2}$  metres. What is the perimeter?

The ratio of lions to tigers in a zoo is 1:3. If there are 12 lions in the zoo, how many tigers do we have?