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E07 • Lesson 7 of 105

Comparing & Ordering

Comparing numbers and fractions, ordering on number line

Elementary Foundations • K-5

Prerequisites: E01, E06

Key Concepts

  • comparison
  • ordering
  • number line

Comparing and Ordering

In everyday life, we constantly compare: Who is taller? Which bag has more candy? Is this fraction bigger or smaller? In this lesson, you will learn how to compare whole numbers and fractions, and how to place numbers in order on a number line.

Comparing Whole Numbers

We use three symbols to compare numbers:

SymbolMeaningExample
>is greater than8 > 5 (eight is greater than five)
<is less than3 < 7 (three is less than seven)
=is equal to4 = 4 (four equals four)

The Alligator Trick

Think of the > and < symbols as an alligator's mouth. The alligator is hungry and always wants to eat the bigger number. The open side of the symbol faces the larger number: 9 > 3 (mouth opens toward 9).

Comparing Big Numbers: 472 vs 468

  1. Compare the hundreds: 4 = 4 (same, so look at the next place).
  2. Compare the tens: 7 > 6.
  3. We can stop here! Since the tens digit is greater, the whole number is greater.
472 > 468

Always compare from left to right, starting with the largest place value.

The Number Line

A number line is a straight line with numbers placed at equal intervals. Numbers get larger as you move to the right and smaller as you move to the left.

0 --- 1 --- 2 --- 3 --- 4 --- 5 --- 6 --- 7 --- 8 --- 9 --- 10

Any number to the right of another number is greater. Any number to the left is smaller. This makes number lines perfect for putting numbers in order.

Ordering Numbers: 7, 2, 9, 4

Find each number on the number line and read from left to right:

2 < 4 < 7 < 9

From least to greatest: 2, 4, 7, 9.
From greatest to least: 9, 7, 4, 2.

Comparing Fractions

Comparing fractions requires a bit more thought. Here are the key strategies:

Same denominator: When two fractions have the same denominator, just compare the numerators. The larger numerator means the larger fraction.

38 < 58    (because 3 < 5 and the pieces are the same size)

Same numerator: When two fractions have the same numerator, the one with the smaller denominator is larger (bigger pieces).

13 > 15    (thirds are bigger pieces than fifths)

Comparing 24 and 26

Both fractions have the numerator 2. Compare the denominators: 4 < 6, which means fourths are larger pieces than sixths.

24 > 26

Two big pieces beat two small pieces!

Benchmark Fractions

It helps to know where common fractions fall compared to 12:

Common Mistake

Students often think bigger numbers always mean bigger fractions. But 18 is NOT bigger than 13, even though 8 is bigger than 3. Remember: the denominator tells you the size of each piece. More pieces means smaller pieces!

Practice Problems

1. Fill in the blank with >, <, or =:   345 ___ 354

Show Solution

Hundreds: 3 = 3. Tens: 4 < 5. So 345 < 354.

2. Order from least to greatest: 58, 85, 41, 14

Show Solution

14, 41, 58, 85. Compare the tens digits first: 1, 4, 5, 8.

3. Which is larger: 58 or 38?

Show Solution

58 is larger. Same denominator, so compare numerators: 5 > 3.

4. Which is larger: 12 or 14?

Show Solution

12 is larger. Same numerator, so the smaller denominator means bigger pieces.

5. Place these fractions in order from least to greatest: 34, 14, 24

Show Solution

14, 24, 34. All have the same denominator, so order the numerators: 1, 2, 3.

Summary: To compare whole numbers, start from the largest place value and work right. For fractions with the same denominator, compare numerators. For fractions with the same numerator, the smaller denominator means a larger fraction. Number lines help you visualize order.

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