Decimal Concepts | Student Worksheet

The Big Idea

Decimals are another way to write fractions with denominators of 10 or 100.

The first place after the decimal point is TENTHS (1/10). The second place is HUNDREDTHS (1/100).

Think of it like money: dimes = tenths and pennies = hundredths!

Example 1: Understanding Tenths

One TENTH = 1/10 = 0.1

1 out of 10 parts = 1/10 = 0.1

3 out of 10 parts = 3/10 = 0.3

Count decimal places: ONE place after the decimal = TENTHS. The number 0.3 has the 3 in the tenths place.

Read it correctly: 0.3 is read as "three tenths" (NOT "zero point three" or "point three").

Example 2: Understanding Hundredths

One HUNDREDTH = 1/100 = 0.01

25/100 = 0.25
25 hundredths = 25 cents!

Ones

Tenths

Hundredths

0.25 = 2 tenths + 5 hundredths = 20/100 + 5/100 = 25/100 = 1/4

TRAP ALERT: Longer Does NOT Mean Larger!

WRONG: Some students think 0.15 > 0.9 because 15 > 9. But that's wrong!

RIGHT: Line up the decimals! 0.9 = 0.90 (add a zero). Now compare: 90 hundredths vs 15 hundredths. 0.90 > 0.15. Think money: 90 cents is more than 15 cents!

Money Helps You Understand Decimals!

1 dollar
= 1.00

10c

1 dime
= 0.10 (1 tenth)

1 penny
= 0.01 (1 hundredth)

25c

1 quarter
= 0.25 = 1/4

Your Turn: Practice Decimal Concepts

1. Write the decimal for 7/10:

710 =

2. Write the fraction for 0.35:

0.35 =

3. Compare these decimals. Write < , > , or =

0.6 0.45

Hint: Rewrite 0.6 as 0.60 to compare.

4. What decimal is shown by the shaded part of this hundred grid?

What fraction is this equal to?

Remember!

Tenths = first place after decimal = denominator of 10
Hundredths = second place after decimal = denominator of 100
0.1 = 1/10 (one tenth) and 0.01 = 1/100 (one hundredth)
Add zeros to compare decimals: 0.5 = 0.50
Use money to check: 0.25 = 25 cents = 1/4 of a dollar
Longer decimals are NOT always larger! Compare place by place.