HSC Minimum Standard Numeracy flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Percentage of a quantity

Convert the percentage to a decimal by dividing by 100, then multiply by the quantity. Example: 25% of 60 = 0.25 × 60 = 15.

Percentage increase or decrease

Subtract the original value from the new value, divide by the original value, then multiply by 100. A positive result is an increase; a negative result is a decrease.

Fraction to decimal

Divide the numerator by the denominator. For example, 3/8 means 3 ÷ 8, which equals 0.375. Multiply the decimal by 100 to express it as a percentage.

Unit rate

The amount for one item or one unit. Divide the total cost or quantity by the number of items, then multiply by the required number of items to scale up.

Simple interest formula

Interest equals principal multiplied by the annual rate as a decimal multiplied by time in years. For $500 at 4% for 3 years: 500 × 0.04 × 3 = $60.

Area of a triangle

Area equals one half multiplied by the base multiplied by the perpendicular height. A triangle with base 10 cm and height 6 cm has area 30 square centimetres.

Area of a circle

Area equals pi multiplied by the radius squared, using pi approximately 3.14. A circle of radius 5 cm has area about 3.14 × 25 = 78.5 square centimetres.

Perimeter of a rectangle

Perimeter equals twice the sum of length and width. A rectangle 8 m long and 3 m wide has perimeter 2 × (8 + 3) = 22 metres.

Volume of a rectangular prism

Volume equals length multiplied by width multiplied by height, given in cubic units. A box 2 m by 3 m by 4 m holds 24 cubic metres.

Mean, median and mode

The mean is the total divided by the count. The median is the middle value once data is ordered. The mode is the most frequent value.

Converting 24-hour time

For afternoon times, add 12 to the hour: 3:20 pm becomes 15:20. Subtract the start time from the finish time to find a duration.

Rounding to nearest whole number

Look at the first digit after the decimal point. If it is 5 or more, round up; if it is 4 or less, keep the whole number unchanged. 7.6 rounds to 8.

Order of operations

Work through brackets first, then powers, then multiplication and division left to right, then addition and subtraction left to right. This order gives one correct result.

Ratio sharing

Add the parts of the ratio to find the total number of parts, divide the amount by that total, then multiply by each part. Share $60 in ratio 2:3 as $24 and $36.

Reading a table

Read the row and column headings first, then find where the required row and column meet. Check whether the table shows totals or averages before using the figures.

Identifying the question asked

Locate the question stem before calculating. Words such as how many, how much, which is cheaper, or how long show what the final answer must be.

Spotting distractor numbers

A numeracy passage often includes figures that are not needed. Identify which values the question actually requires and ignore the rest rather than combining all numbers.

Qualifier words in questions

Words such as approximately, at least, per person, excluding, and before tax change the calculation. Underline them before choosing an operation or an answer option.

Matching units before comparing

Values must be in the same unit before comparison. Convert metres to centimetres by multiplying by 100, or minutes to hours by dividing by 60, then compare.

Graph axis scale

Check the numbers and spacing on each axis. Uneven or non-zero starting scales can make small differences look large, so read the labelled values rather than the bar heights.

Inference versus stated fact

A stated fact appears directly in the text. An inference is a conclusion the text supports but does not say outright, so choose the option backed by evidence.

Conditional instructions

Instructions using if or when apply only in the stated situation. Follow the steps in the order given and apply a conditional step only when its condition is true.

Locating key information

Scan for numbers, units, and question keywords rather than reading every word equally. Mark the sentence that contains the data needed for the calculation.

Interpreting a receipt

A receipt lists item prices, any discount, and a total. Subtract discounts before adding, and check that the stated total matches the sum of the items.

Showing working in responses

Write the calculation line before the final answer, for example 3 × $4.50 = $13.50. Method marks are often awarded even when the final figure is incorrect.

Justifying a comparison

State the compared values and the direction of the difference. Write that Shop A is cheaper because $2.40 is less than $2.55, rather than only naming the cheaper shop.

Labelling units in answers

Attach the correct unit to every number in a written response, such as dollars, metres, or minutes. An unlabelled figure can be read as the wrong quantity.

Whole-number answers

When the question asks how many whole items are needed, round up if any amount remains. For 23 people in cars of 5 seats, 4.6 becomes 5 cars.

Sequencing a written procedure

Use markers such as first, then, and finally, one step per sentence. This makes the order of operations clear to a reader following the method.

Explaining an error

Name the step that went wrong, state why it is wrong, and give the corrected value. For example, the units were not converted, so the correct total is 250 cm.

Avoiding vague quantifiers

Replace words such as some, a lot, and nearly all with the calculated figure or a stated range so the claim can be checked against the data.

Answering the question asked

Reread the question after calculating and confirm the response gives the requested quantity, unit, and form, such as a cost, a duration, or a number of items.