Question

Please help me convert 0.42 into a simplified fraction.

Answer 1

0.42 is the same as 42/100.
42 and 100 both can be divided by two (aka both have a factor of 2) so you can simplify it further to 21/50.
21's factors are 1,3,7,21. 50's factors are 1,2,5,10,25,50. The only matching factors are 1, which does not allow us to simplify further.
Therefore, the simplified fraction is 21/50. You can always turn a decimal to a fraction this way.