which one is largest

In fact 0.46 is the largest and here is why.

0.46 has the largest value in the tenths column. That is the largest number directly to the right of the decimal point.

Think of it like this, would you rather I give you:

$0.13 (13 cents)
$0.46 (46 cents)
$0.30 (30 cents)
$0.21 (21 cents)

obviously 46 cents is better than 30 cents or 21 cents or 13 cents.

Just because you have more numbers to the right of the decimal point does not mean it is a larger number. take this for example:

Would you rather have 9.0 cars or 5.00 cars?

obviously 9 cars is better than 5 cars. Even though the 5 has more zeros to the right of the decimal point.

Do you understand?