Comparing decimals, step by step

Comparing decimals catches the classic trap — thinking 0.45 is bigger than 0.5 because it has more digits.

The question

3.4 ? 3.40

3.4?3.40
3.40?3.40
3.40?3.40
340 hundredths=340 hundredths
3.4=3.40
  1. These count different sized pieces — one is in bigger pieces and the other is not. Longer does NOT mean bigger with decimals, so the first job is to make the pieces match.
  2. Write a zero on the end of the shorter one. 3.4 is the same amount as 3.40 — a zero on the END of a decimal changes nothing.
  3. Now they are both hundredths: 340 against 340. The same. So 3.4 = 3.40.

How it works.

  1. 01

    These count different sized pieces — one is in bigger pieces and the other is not. Longer does NOT mean bigger with decimals, so the first job is to make the pieces match.

  2. 02

    Write a zero on the end of the shorter one. 3.4 is the same amount as 3.40 — a zero on the END of a decimal changes nothing.

  3. 03

    Now they are both hundredths: 340 against 340. The same. So 3.4 = 3.40.