Curriculum›4B›Chapter 12

Comparing and Ordering Decimals

Semester 4B · Chapter 12 · Lesson 7 · MATH-4B-C12-L07

Learning goal: Compare and order decimals by aligning place values and using number lines.

Before you begin: prerequisite check

Recall: 12.01–12.06. Attempt these questions independently first.

Question 1 · decimal

Write 11/20 as a decimal.

Show answer and reasoning
0.55

Rename 11/20 in tenths or hundredths (or divide numerator by denominator) to get 0.55.

Question 2 · decimal

Write 1/4 as a decimal.

Show answer and reasoning
0.25

Rename 1/4 in tenths or hundredths (or divide numerator by denominator) to get 0.25.

Question 3 · decimal

Write 1/10 as a decimal.

Show answer and reasoning
0.1

Rename 1/10 in tenths or hundredths (or divide numerator by denominator) to get 0.1.

Key vocabulary

tenth
one of ten equal parts of a whole
hundredth
one of one hundred equal parts
equivalent decimals
two notations for the same amount
midpoint
exact halfway point between rounding benchmarks

Understand the concept

To compare decimal numbers, first align the ones, tenths, and hundredths. For example, 0.6 = 0.60, and 0.60 is greater than 0.57 because 60 hundredths are more than 57 hundredths. A longer string of digits after the decimal point does not necessarily mean a larger quantity. A number line or grid can confirm the comparison. For ordering three decimals, write them with the same number of decimal places before comparing left to right.

Common misunderstanding to avoid: Thinking 0.45 is less than 0.5 because 45 > 5 logic reversed

Fully worked examples and immediate checks

Read each example, predict how to begin, then follow its numerical explanation. The check below it is a fresh problem.

Worked example 1

Question 1 · comparison

Insert <, > or =: 0.75 ___ 0.24.

Answer: >

Compare 75 hundredths and 24 hundredths; 0.75 is greater relative to 0.24.

Check 1: try it yourself

Question 1 · comparison

Insert <, > or =: 0.46 ___ 0.10.

Show answer and reasoning
>

Compare 46 hundredths and 10 hundredths; 0.46 is greater relative to 0.10.

Worked example 2

Question 2 · comparison

Insert <, > or =: 0.94 ___ 0.96.

Answer: <

Compare 94 hundredths and 96 hundredths; 0.94 is less relative to 0.96.

Check 2: try it yourself

Question 2 · comparison

Insert <, > or =: 0.14 ___ 0.14.

Show answer and reasoning
=

Compare 14 hundredths and 14 hundredths; 0.14 is equal relative to 0.14.

Worked example 3

Question 3 · comparison

Insert <, > or =: 0.13 ___ 0.55.

Answer: <

Compare 13 hundredths and 55 hundredths; 0.13 is less relative to 0.55.

Check 3: try it yourself

Question 3 · comparison

Insert <, > or =: 0.66 ___ 0.20.

Show answer and reasoning
>

Compare 66 hundredths and 20 hundredths; 0.66 is greater relative to 0.20.

Guided practice

Question 1 · comparison

Insert <, > or =: 0.37 ___ 0.94.

Show answer and reasoning
<

Compare 37 hundredths and 94 hundredths; 0.37 is less relative to 0.94.

Question 2 · comparison

Insert <, > or =: 0.44 ___ 0.54.

Show answer and reasoning
<

Compare 44 hundredths and 54 hundredths; 0.44 is less relative to 0.54.

Question 3 · comparison

Insert <, > or =: 0.85 ___ 0.35.

Show answer and reasoning
>

Compare 85 hundredths and 35 hundredths; 0.85 is greater relative to 0.35.

Question 4 · ordering

Order 0.87, 0.59, and 0.11 from least to greatest.

Show answer and reasoning
0.11, 0.59, 0.87

Convert all to hundredths and sort the integer counts.

Question 5 · ordering

Order 0.18, 0.60, and 0.82 from least to greatest.

Show answer and reasoning
0.18, 0.60, 0.82

Convert all to hundredths and sort the integer counts.

Independent practice

Question 1 · comparison

Insert <, > or =: 0.59 ___ 0.83.

Show answer and reasoning
<

Compare 59 hundredths and 83 hundredths; 0.59 is less relative to 0.83.

Question 2 · comparison

Insert <, > or =: 0.15 ___ 0.49.

Show answer and reasoning
<

Compare 15 hundredths and 49 hundredths; 0.15 is less relative to 0.49.

Question 3 · comparison

Insert <, > or =: 0.71 ___ 0.91.

Show answer and reasoning
<

Compare 71 hundredths and 91 hundredths; 0.71 is less relative to 0.91.

Question 4 · ordering

Order 0.89, 0.22, and 0.17 from least to greatest.

Show answer and reasoning
0.17, 0.22, 0.89

Convert all to hundredths and sort the integer counts.

Question 5 · ordering

Order 0.95, 0.45, and 0.80 from least to greatest.

Show answer and reasoning
0.45, 0.80, 0.95

Convert all to hundredths and sort the integer counts.

Question 6 · comparison

Insert <, > or =: 0.85 ___ 0.62.

Show answer and reasoning
>

Compare 85 hundredths and 62 hundredths; 0.85 is greater relative to 0.62.

Question 7 · comparison

Insert <, > or =: 0.86 ___ 0.33.

Show answer and reasoning
>

Compare 86 hundredths and 33 hundredths; 0.86 is greater relative to 0.33.

Question 8 · comparison

Insert <, > or =: 0.73 ___ 0.56.

Show answer and reasoning
>

Compare 73 hundredths and 56 hundredths; 0.73 is greater relative to 0.56.

Challenge and transfer

Use a diagram or verbal justification where appropriate. The goal is transfer rather than speed.

Question 1 · reasoning

Insert <, > or =: 0.41 ___ 0.87. Explain how place value or a model can check your result.

Show answer and reasoning
<

Compare 41 hundredths and 87 hundredths; 0.41 is less relative to 0.87. A correct explanation should name the relevant fractional place values and verify the answer.

Question 2 · error analysis

A learner claims: “0.45 is greater than 0.5 because 45 is greater than 5.” Identify what is wrong or incomplete and give a mathematically correct explanation.

Show answer and reasoning
False: 0.5 = 0.50, and 45 hundredths are fewer than 50 hundredths.

False: 0.5 = 0.50, and 45 hundredths are fewer than 50 hundredths. Explain the relevant quantities or properties, not merely the final answer.

Exit check

Question 1 · comparison

Insert <, > or =: 0.98 ___ 0.26.

Show answer and reasoning
>

Compare 98 hundredths and 26 hundredths; 0.98 is greater relative to 0.26.

Question 2 · comparison

Insert <, > or =: 0.41 ___ 0.71.

Show answer and reasoning
<

Compare 41 hundredths and 71 hundredths; 0.41 is less relative to 0.71.

Question 3 · comparison

Insert <, > or =: 0.86 ___ 0.73.

Show answer and reasoning
>

Compare 86 hundredths and 73 hundredths; 0.86 is greater relative to 0.73.

Mastery check: Solve a new instance without hints, explain why the method works, and return later to confirm retention.