Compare and Order Decimals

Decimals describe parts of a whole using place values smaller than 1. To compare or order decimals, line up the decimal points so the same place values stack. Then scan from the largest place to the smallest, just like you do with whole numbers.

Line Up the Decimal Points

1. Stack the two decimals so the decimal points sit one above the other.
2. Add zeros at the right end so each decimal has the same number of places (0.27 becomes 0.270 to compare with 0.270).
3. Scan left to right starting at the greatest place: ones, tenths, hundredths, thousandths.
4. The first place where the digits differ tells you which decimal is greater.

Adding Zeros Does Not Change the Value

• 0.3 and 0.30 and 0.300 are all the same number — equivalent decimals.
• Trailing zeros after the decimal point hold the place but do not change the value.
• This trick lets you give two decimals the same number of digits before comparing.
• Be careful: 0.30 equals 0.3, but 0.03 does NOT — the 3 is in a different place.

Compare Step by Step

• Same ones digit? Move to the tenths place.
• Same tenths? Move to the hundredths place.
• Same hundredths? Move to the thousandths place.
• The first place where the digits differ wins — bigger digit means bigger decimal.

Use 0.5 as a Benchmark

• 0.5 is the same as 1/2 — exactly halfway between 0 and 1.
• A decimal is less than 0.5 when its tenths digit is 0, 1, 2, 3, or 4 (like 0.27 or 0.49).
• A decimal is greater than 0.5 when its tenths digit is 6, 7, 8, or 9 (like 0.6 or 0.85).
• When the tenths digit is exactly 5, look at the hundredths to decide: 0.50 equals 0.5, 0.52 is greater, 0.49 is less.