Place Value with Decimals (Thousandths) • Topic 3 of 3

Comparing Decimals

How to Compare Decimals:

Method 1: Use Place Value

Compare whole numbers first
If whole numbers are equal, compare tenths
If tenths are equal, compare hundredths
Continue to thousandths if needed

Method 2: Use Common Denominator

0.8 = 8/10 = 80/100
0.79 = 79/100
80/100 > 79/100, so 0.8 > 0.79

Method 3: Use Number Line

Numbers to the right are greater

COMPARING DECIMALS NUMBER LINE:

    0.79        0.8
      │          │
      ▼          ▼
      ├──────────┤
      │          │
      
    0.75  0.76  0.77  0.78  0.79  0.80  0.81  0.82
      │     │     │     │     │     │     │     │
      
    0.79 < 0.8  (0.79 is to the left)


PLACE VALUE COMPARISON:

    Number A: 5 . 6 7 8
    Number B: 5 . 6 8 2
    
    Step 1: Whole numbers = (5 = 5) ✓
    Step 2: Tenths = (6 = 6) ✓
    Step 3: Hundredths: 7 vs 8 → 7 < 8
    Conclusion: 5.678 < 5.682

Solved Examples

Worked Example

Compare: 0.8 and 0.79

Solution (Place Value):

0.8 = 0.80 (add zero to compare)
Compare tenths: 8 vs 7
8 > 7, so 0.8 > 0.79

Solution

Worked Example

Compare: 3.245 and 3.25

Solution

Write with same places: 3.250
Compare: 3.245 vs 3.250
Hundredths: 4 vs 5 → 4 < 5
So 3.245 < 3.25

Worked Example

Arrange in ascending order: 0.5, 0.52, 0.502

Solution

Write with same decimal places: 0.500, 0.520, 0.502
Compare: 0.500 < 0.502 < 0.520
Answer: 0.5, 0.502, 0.52

Key Points

Add zeros to make same number of decimal places
Compare left to right (whole → tenths → hundredths → thousandths)
> means "greater than"
< means "less than"
= means "equal to"

Quick Check — 4 MCQs

Tap an option to check your answer0 / 4

Q1.To compare decimals, first line up the:

Explanation: Decimal points.

Q2.Which is greater: $0.5$ or $0.45$?

Explanation: $0.5=0.50>0.45$.

Q3.$0.30$ is ___ $0.3$.

Explanation: Equal.

Q4.Adding zeros to the right of a decimal:

Explanation: No change in value.

Practice more MCQs → 📝 Assignment · 35 marks