Comparing and Ordering Decimals
Compare digit by digit from the left starting at the largest place value.
Key idea
Compare digit by digit from the left starting at the largest place value.
In depth
Pad with zeros so numbers have the same number of decimal places, then compare as if whole numbers. Compare place by place from the left.
Worked example
Compare 0.7 and 0.65: write 0.70 and 0.65; 70 > 65 so 0.7 > 0.65.
Real-world uses
- Comparing sports results such as 9.85 s and 9.9 s
- Choosing the lowest unit price on a shelf
Common mistake
Assuming more digits means a bigger number. 0.65 has more digits but is smaller than 0.7.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Comparing and Ordering Decimals?
Compare digit by digit from the left starting at the largest place value. It is a topic at the intermediate level in Arithmetic & Number Sense.
Where is Comparing and Ordering Decimals used in real life?
Real-world examples: Comparing sports results such as 9.85 s and 9.9 s; Choosing the lowest unit price on a shelf.
What should I learn before Comparing and Ordering Decimals?
Make sure you are comfortable with Decimals, the previous topic in Arithmetic & Number Sense.
What is a common mistake with Comparing and Ordering Decimals?
Assuming more digits means a bigger number. 0.65 has more digits but is smaller than 0.7.
How can I practise Comparing and Ordering Decimals?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Comparing and Ordering Decimals?
Move on to Adding and Subtracting Decimals next.
Related intermediate topics in Arithmetic & Number Sense
- Long Multiplication – Multiply by each digit of the multiplier, shift by place value, then add partial products.
- Long Division – Divide, multiply, subtract and bring down repeatedly to get the quotient.
- Factors and Multiples – Factors divide a number exactly; multiples are its products with whole numbers.
- Divisibility Rules – Quick tests: by 2 last digit even, by 3 digit-sum divisible by 3, by 5 ends 0/5, by 9 digit-sum divisible by 9.
- Prime Numbers – A prime has exactly two positive divisors: 1 and itself.
- Composite Numbers – Numbers greater than 1 with more than two factors.