Question

Arwa is playing 'Guess my number'. Arwa says: 'If I add 0.4 to my number, divide the answer by 8, then multiply that answer by 9, I get 0.9.' What is Arwa's number?

Answer 1

0.4 is the answer because you if you work backwards and use inverse operations you get 0.4.
meaning, if you divide 0.9 by 9, you get 0.1. when you multiply 0.1 and 8 you get 0.8. and when you subtract 0.4 from 0.8 you get your answer, 0.4.