GCSE Maths Practice: place-value-and-rounding
This foundation-level question checks your ability to round decimals to the nearest tenth. You only need to look one digit past the tenths place to decide whether to round up or stay the same.
Exam tip: Always mark the digit you’re rounding to and circle the next one. If that digit is 5 or more, round up; if less, keep the same. Visualising on a number line makes rounding much easier.
Try more: 5.48, 7.05, 12.95.
Concept Overview
Rounding to the nearest tenth means finding the closest value that has one digit after the decimal point. This skill is very common in everyday life — whether you are measuring lengths in science, recording prices in a shop, or timing a race. The tenths place is the first digit after the decimal point, and it represents one-tenth (0.1) of a whole unit. To round to this place, you look one digit further to the right: the hundredths place.
The rule is simple: if the hundredths digit is 5 or more, round the tenths digit up by one; if it is 4 or less, keep the tenths digit the same. Rounding helps make decimals easier to compare, estimate, or record, especially when an exact value isn’t needed. For example, when weighing ingredients or measuring time, it’s easier to read 6.2 than 6.23.
Step-by-Step Method
- Identify the tenths digit: In 6.23, the tenths digit is 2.
- Look at the next digit (hundredths): 3 tells us whether to round up or keep the same.
- Apply the rule: 3 < 5 → keep the tenths digit as 2.
- Write the rounded number: Replace everything after the tenths with nothing (or zeros). Result = 6.2.
Worked Examples
Example 1. Round 9.67 to the nearest tenth.
- Tenths = 6, Hundredths = 7.
- Since 7 ≥ 5 → round up → 9.7.
Example 2. Round 2.14 to the nearest tenth.
- Tenths = 1, Hundredths = 4.
- Since 4 < 5 → keep 1 → 2.1.
Example 3 (Edge Case). Round 4.95 to the nearest tenth.
- Tenths = 9, Hundredths = 5.
- Round up → 9 → 10 → 5.0 (the 0 shows the tenths place).
Common Mistakes
- Using the wrong digit: Many students accidentally look at the ones digit (the digit before the decimal) instead of the hundredths digit.
- Adding an unnecessary digit: 6.25 is rounding to the nearest hundredth, not tenth.
- Forgetting place value meaning: Remember: tenths = one digit after the decimal; hundredths = two digits after the decimal.
- Dropping trailing zeros incorrectly: 5.0 is different from 5 — the zero shows you’ve rounded to the tenths place.
Real-Life Applications
Rounding to tenths is used every day in measurement and estimation. For example:
- Science experiments: Thermometers often display readings like 23.4°C, rounded to the nearest tenth.
- Shopping: Prices like £6.23 are often rounded to £6.20 for quick mental calculations.
- Sports timing: Sprint times, like 10.26 seconds, are rounded to 10.3 seconds for display.
In all these cases, rounding makes numbers easier to use without losing meaningful accuracy.
FAQ
Q1: How do I know if I’m rounding to the tenth or hundredth?
A: The tenth is the first digit after the decimal point; the hundredth is the second digit.
Q2: What if the hundredths digit is exactly 5?
A: Always round up. Example: 4.35 → 4.4.
Q3: Why does 6.23 become 6.2 and not 6.3?
A: Because 6.23 is closer to 6.2 (the midpoint 6.25 would round up).
Study Tip
Draw a number line from 6.2 to 6.3 to visualise rounding. Place 6.23 between them — it lies before the midpoint 6.25, so it rounds down to 6.2. Visual tools like this help you quickly judge which rounded number is closest.