Assessed mathematical skills and measurement conventions
Start with Concept to understand a topic, then use Question Bank to check what you know.
Your progress
Sign in to see your mastery and mistakes.
A.0 Arithmetic and numerical computation
A.0.1—Units in calculations
Recognise and use appropriate units in calculations, including converting units such as mm³ to cm³ in volumetric calculations and determining units for rates such as breathing rate.
A.0.2—Decimal and standard form
Recognise and use decimal and standard form; choose appropriate decimal places; calculate with ordinary and standard form; apply standard form to organelle sizes; convert between forms while retaining significant figures, for example 0.0050 mol dm⁻³ = 5.0 × 10⁻³ mol dm⁻³.
A.0.3—Ratios, fractions and percentages
Use ratios, fractions and percentages, including percentage yields, surface-area-to-volume ratios, measurement scales and phenotypic ratios in monohybrid and dihybrid crosses.
A.0.4—Estimating results
Estimate results to sense-check whether calculated values are appropriate.
A.0.5—Powers, exponentials and logarithms
Use calculators to find and use power, exponential and logarithmic functions, including estimating bacterial population growth over time.
A.0.P—SI unit prefixes
Know and convert between the SI prefixes kilo, centi, milli, micro and nano, as clarified by Pearson for International A Level Biology candidates.
A.1 Handling data
A.1.1—Significant figures
Use an appropriate number of significant figures; report calculated results consistently with the precision of the raw data and the least accurate measurement.
A.1.2—Arithmetic means
Calculate arithmetic means from biological data, such as mean stomatal counts.
A.1.3—Tables, diagrams, bar charts and histograms
Construct and interpret frequency tables and diagrams, bar charts and histograms; use clear headings, units and consistent decimal places; select suitable formats and interpret biological tables and graphs such as enzyme-activity graphs and ECG traces.
A.1.4—Simple probability
Understand simple probability and use probability and chance appropriately, including in genetic inheritance.
A.1.5—Sampling scientific data
Understand sampling principles for scientific data, including analysing randomly collected data and calculating an index of diversity to compare habitats.
A.1.6—Mean, median and mode
Understand and calculate or compare the mean, median and mode of biological datasets.
A.1.7—Scatter diagrams and correlation
Use scatter diagrams to identify correlations between variables, for example between lifestyle factors and health.
A.1.8—Order-of-magnitude calculations
Make order-of-magnitude calculations, including manipulating magnification = image size ÷ real-object size.
A.1.9—Statistical tests
Select and use statistical tests, including chi-squared tests for observed versus expected results, Student's t-tests and correlation coefficients.
A.1.10—Dispersion, standard deviation and range
Understand measures of dispersion, including range and standard deviation; calculate standard deviation and judge when it is more useful, including when data contain an outlier.
A.1.11—Measurement uncertainty
Identify measurement uncertainties and use simple techniques to determine uncertainty when data are combined, including calculating percentage error.
A.2 Algebra
A.2.1—Mathematical symbols
Understand and use the symbols =, <, ≪, ≫, >, ∝ and ~.
A.2.2—Changing the subject of an equation
Change the subject of an equation and manipulate equations in biological contexts such as magnification.
A.2.3—Substitution into algebraic equations
Substitute numerical values into algebraic equations using appropriate physical units, including using a supplied formula to calculate an index of diversity.
A.2.4—Solving algebraic equations
Solve algebraic equations in biological contexts, for example cardiac output = stroke volume × heart rate.
A.2.5—Logarithmic quantities
Use logarithms for quantities spanning several orders of magnitude, including logarithmic scales for microorganism growth.
A.3 Graphs
A.3.1—Translating between data forms
Translate information between graphical, numerical and algebraic forms, including using data represented by dissociation curves.
A.3.2—Plotting two variables
Plot two variables from experimental or other data and select appropriate formats such as bar charts, histograms, graphs and scattergrams.
A.3.3—Linear relationships
Understand that y = mx + c represents a linear relationship and predict or sketch linear graphs in biological contexts.
A.3.4—Graph intercepts
Determine a graph intercept, including reading an intercept such as the compensation point in plants.
A.3.5—Rates from linear graphs
Calculate rate of change from a graph showing a linear relationship, for example transpiration rate.
A.3.6—Tangents and instantaneous rates
Draw and use the slope of a tangent to a curve as a measure of rate of change, such as product formation at a point on an enzyme-reaction curve.
A.4 Geometry and trigonometry
A.4.1—Circumference, area and volume
Calculate circumferences, surface areas and volumes of regular shapes, including circles, rectangular and cylindrical prisms and spheres, and apply these calculations to cells.