Oh, tough one! Let's look at this 2 ways and you decide which works for you.
Remember that you can add zeroes after the last digit after the decimal and still have the result be equal.
0.2 = 0.20 = 0.200, etc
With that being said, which is bigger, 0.20 or 0.79. Well, gosh, 0.79 is bigger!
Let's also look at their "names."
0.2 = two tenths = 2/10
0.79 = seventy nine hundredths = 79/100
Well, we can make 2/10 into 20/100 (aka 0.20) and see that 79/100 > 20/100.
Hope this helps!