How do you order numbers and calculate accurately with the four operations, directed numbers and the correct order of operations?
Order positive and negative integers, decimals and fractions; use the four operations with whole numbers, decimals and directed numbers; and apply the correct order of operations (BIDMAS), including brackets, powers and roots.
A focused answer to the Eduqas GCSE Mathematics number content on the structure of the number system and calculation, covering ordering, the four operations, directed numbers, and the order of operations (BIDMAS).
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What this dot point is asking
The Eduqas number content opens with the structure of the number system and calculation: ordering integers, decimals and fractions, calculating with the four operations including directed (signed) numbers, and applying the order of operations. This is the bedrock of the whole qualification. Both components test it, and because Component 1 is non-calculator, fluent written and mental arithmetic is essential. A sign slip or an order-of-operations error in the first line of working carries through every later step, so accuracy here protects marks across the entire paper.
Ordering numbers
To order a mixed list of integers, decimals and fractions, put them all in one form first.
For decimals, line up the decimal points and pad with trailing zeros so each has the same number of places: become , which order easily. For fractions, rewrite them over a common denominator: over are , so the order is . With negative numbers, remember the number line: is smaller than , because it lies further left.
The four operations and directed numbers
Adding and subtracting directed numbers is where most marks are lost.
So (unlike signs), (like signs), and . A number line helps with the additions and subtractions: start at the first number and step right for or left for . Distinguishing position (which can be negative) from distance (which cannot) is a recurring exam theme, as in temperature, depth and bank-balance problems.
The order of operations (BIDMAS)
When an expression mixes operations, the order is fixed.
So : the power, then the multiplication, then the addition. Division and multiplication share a level, so is worked left to right as , not . Treating a fraction bar as a bracket matters: , evaluating top and bottom before dividing.
Why this matters
Calculation underpins every other area of the Eduqas course, from compound measures to probability to solving equations. Because AO1 (using standard techniques) is half of the marks and AO2 and AO3 reward clear reasoning, accurate signed arithmetic and a correct order of operations are constantly assumed rather than re-tested in isolation. Securing them frees attention for the harder reasoning that earns the top grades.
Exam-style practice questions
Practice questions written in the style of WJEC Eduqas exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
Eduqas 20193 marksWork out . (Foundation, Component 1, non-calculator.)Show worked answer β
Apply BIDMAS: multiplication before addition and subtraction.
Multiplication first: .
Now work left to right: , then .
Markers award a mark for the correct product , a mark for handling the double negative , and a mark for the final answer . The usual error is to work strictly left to right and add before multiplying.
Eduqas 20214 marksA diver is at m relative to sea level. She descends a further m, then rises m. Find her final depth, and find the total vertical distance she travels. (Foundation, Component 2, calculator.)Show worked answer β
Track the directed numbers for the final depth, but add absolute distances for the total travelled.
Final depth: , so she is at m (14 m below sea level).
Total distance travelled: she moves m down then m up, so m.
Markers give marks for the correct signed arithmetic, the final position m, recognising distance ignores direction, and the total m. Subtracting to get for the distance is the common slip; distance is never negative.
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Sources & how we know this
- WJEC Eduqas GCSE (9-1) Mathematics specification (C300) β WJEC Eduqas (2015)