Rounding To Decimal Places - GCSE Maths Revision - BBC Bitesize

In this guide

1. Revise
2. Test

Pages

1. What is approximation?
2. Rounding to decimal places
3. Rounding to significant figures
4. Truncation
5. Estimating calculations
6. Upper and lower bounds
7. Apply and interpret limits of accuracy - Higher

Rounding to decimal places

When rounding using decimal places (dp), the degree of accuracy that is required is usually given. However, there are certain calculations where the degree of accuracy may be more obvious. For example, calculations involving money should be given to two decimal places to represent the pence.

To round to a decimal place:

1. look at the first digit after the decimal point if rounding to one decimal place or the second digit for two decimal places
2. draw a vertical line to the right of the place value digit that is required
3. look at the next digit
4. if it's 5 or more, increase the previous digit by one
5. if it's 4 or less, keep the previous digit the same
6. remove any numbers to the right of the line

Examples

Round 248.561 to 1 decimal place, then 2 decimal places.

• 248.5|61 to 1 decimal place is 248.6
• 248.56|1 to 2 decimal places is 248.56

Notice that your answer should have the same number of decimal places as the approximation asked for.

Round 0.08513 to 1 and 2 decimal places.

• 0.0|8513 to 1 decimal place is 0.1
• 0.08|513 to 2 decimal places is 0.09

Question

Round 249.5046 to 1, then 2 decimal places.

Show answer

• 249.5|046 to 1 decimal place is 249.5
• 249.50|46 to 2 decimal places is 249.50

Notice that 249.50 = 249.5. However, as the question asked for 2 decimal places both numbers are left.

Question

Round 0.9583 to 1 decimal place, then 2 decimal places.

Show answer

• 0.9|583 to 1 decimal place is 1.0
• 0.95|83 to 2 decimal places is 0.96

Question

Round 598.053 to 1 decimal place, then 2 decimal places.

Show answer

• 598.0|53 to 1 decimal place is 598.1
• 598.05|3 to 2 decimal places is 598.05

Next pageRounding to significant figuresPrevious pageWhat is approximation?

More guides on this topic

• NEW: Whole numbers
• NEW: Order of operations and negative numbers
• NEW: Decimals
• NEW: Converting between fractions, decimals and percentages
• NEW: Higher – How to convert recurring decimals
• NEW: How to round numbers
• NEW: What is accuracy in maths?
• NEW: What are fractions?
• NEW: How to add, subtract, multiply and divide fractions
• NEW: Multiples and factors
• NEW: Highest Common Factor and Lowest Common Multiple
• NEW: Laws of indices
• NEW: Negative and fractional indices
• NEW: Standard form
• NEW: Calculations using standard form
• Whole numbers - Edexcel
• Decimals - Edexcel
• Multiples and factors - Edexcel
• Standard form - Edexcel
• Laws of indices - Edexcel
• Fractions - Edexcel
• Converting between fractions, decimals and percentages - Edexcel
• Surds - Higher - Edexcel
• Financial mathematics - Edexcel

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