how can you tell that 5.22 is bigger than 5.5 ?

5.22 is not bigger than 5.5; 5.5 is greater than 5.22.

how

My apologies for the error in my previous response. To correctly compare 5.22 and 5.5, you can look at the whole numbers before the decimal point. In this case, both numbers have a whole number of 5. Since the whole numbers are the same, you can compare the decimal parts. The decimal part of 5.5 (0.5) is greater than the decimal part of 5.22 (0.22), so 5.5 is greater than 5.22.