Understanding Decimals

Learn about tenths and hundredths

Understanding Decimals

What Are Decimals?

Decimals are another way to show parts of a whole.

Place Value with Decimals

Example: 3.453.45

| Ones | . | Tenths | Hundredths | |------|---|--------|------------| | 3 | . | 4 | 5 |

  • 3 is in the ones place
  • 4 is in the tenths place (4 tenths = 410\frac{4}{10})
  • 5 is in the hundredths place (5 hundredths = 5100\frac{5}{100})

Reading Decimals

  • 0.30.3 → "three tenths"
  • 0.450.45 → "forty-five hundredths"
  • 2.72.7 → "two and seven tenths"

Decimals and Fractions

Decimals are related to fractions:

  • 0.1=1100.1 = \frac{1}{10}
  • 0.5=510=120.5 = \frac{5}{10} = \frac{1}{2}
  • 0.25=25100=140.25 = \frac{25}{100} = \frac{1}{4}

Money Connection

Money uses decimals!

  • \0.25$ = 25 cents = one quarter
  • \0.50$ = 50 cents = one half dollar

📚 Practice Problems

1Problem 1easy

❓ Question:

What decimal represents "five tenths"?

💡 Show Solution

Solution:

"Five tenths" means 5 in the tenths place:

0.50.5

This is the same as 510\frac{5}{10}

Answer: 0.50.5

2Problem 2medium

❓ Question:

Write 310\frac{3}{10} as a decimal.

💡 Show Solution

Solution:

The denominator 10 tells us this is tenths. Put 3 in the tenths place:

310=0.3\frac{3}{10} = 0.3

Answer: 0.30.3

3Problem 3hard

❓ Question:

Write 47100\frac{47}{100} as a decimal.

💡 Show Solution

Solution:

The denominator 100 tells us this is hundredths. 47 hundredths:

47100=0.47\frac{47}{100} = 0.47

Answer: 0.470.47

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