Kristy has 100 buttons in her button collection. she has 24 red buttons. write a decimal to show the part of her collection of 4 the buttons that is red.

The decimal that represents the 24 red buttons in her collection is 0.24.  The reason the number remains the same is because this is the number out of 100 total.  Decimals that end two places to the right of the decimal point are in the hundredths place.