Bramhall High school Year 8 Assessment Descriptors Mathematics

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1 Grade Description Calculate with negative indices in the context of standard form. 8/9 Multiply (divide) numbers written in standard form. Use inequalities to describe the range of values for a rounded value. Solve problems involving the maximum and minimum values of an amount that has been rounded. Know how to deal with a change in depth when dealing with plans and elevations. Construct a shape from its plans and elevations. Construct the plan and elevations of a given shape. Expand the expression (x ± a) 2. Identify when it is necessary to remove factors to factorise a quadratic expression. Identify when it is necessary to find two linear expressions to factorise a quadratic expression. Factorise a quadratic expression of the form x² + bx + c Know how to set up an mathematical argument. Work out why two algebraic expressions are equivalent. Create a mathematical argument to show that two algebraic expressions are equivalent. Distinguish between situations that can be modelled by an expression or a formula. Create an expression or a formula to describe a situation. Substitute numbers into formulae including terms in x 2 Generate terms of a quadratic sequence from a written rule. Generate terms of a quadratic sequence from its nth term. Identify quadratic sequences. Establish the first and second differences of a quadratic sequence. Find the next three terms in any quadratic sequence. Know the difference between direct and inverse proportion. Recognise direct (inverse) proportion in a situation. Know the features of a graph that represents a direct (inverse) proportion situation. Know the features of an expression (or formula) that represents a direct (inverse) proportion situation. Understand the connection between the multiplier, the expression and the graph. Solve two linear simultaneous equations in two variables in simple cases (multiplication of one equation only required). Interpret the solution to a pair of simultaneous equations. Plot/sketch/recognise/interpret graphs of cubic, reciprocal functions. Plot and interpret graphs of non-standard functions in real contexts. Know the structure of a simple mathematical proof. Use known facts to create simple proofs. Solve problems which include calculations with improper fractions and 6/7 mixed numbers, positive and negative, brackets and indices. Calculate with positive indices (roots) using written methods. Add (subtract) numbers written in standard form. Convert a near miss into standard form; e.g Enter a calculation written in standard form into a scientific calculator. Interpret the standard form display of a scientific calculator. Understand the difference between truncating and rounding. Identify the minimum and maximum values of an amount that has been rounded (to nearest x, x d.p., x s.f.) Exceeding

2 Identify when a perpendicular bisector is needed to solve a loci problem. Identify when an angle bisector is needed to solve a loci problem. Choose techniques to construct 2D shapes; e.g. rhombus. Combine techniques to solve more complex loci problems. Identify common factors (numerical and algebraic) of terms in an expression. Factorise an expression by taking out common factors. Change the subject of a formula when a two steps are required. Understand the meaning of an identity. Multiply two linear expressions of the form (x ± a)(x ± b). Solve financial problems including simple interest. Understand the meaning of giving an exact solution. Solve problems that require exact calculation with fractions. Know the vocabulary of circles. Know how to find arc length when radius is given. Know how to find the area of a sector when radius is given. Calculate the angle of a sector when the arc length and radius are known. Know how to find the surface area of a right prism (cylinder). Calculate exactly with multiples of π. Identify the hypotenuse in a right-angled triangle. Know when to apply Pythagoras theorem for calculating the hypotenuse or one of the shorter sides in a right-angled triangle. Know the meaning of congruent (similar) shapes. Identify congruence (similarity) of shapes in a range of situations. Identify the information required to solve a problem involving similar shape. Finding missing lengths in similar shapes. Understand why speed, density and pressure are known as compound units. Know the definition of density (pressure, population density, speed). Solve problems involving density (pressure, speed). Convert between units of density. Know how to deal with negative number terms in an inequality. Use a number line to find the set of values that are true for two inequalities. Understand the concept of simultaneous equations. Find approximate solutions to simultaneous equations using a graph. Understand the concept of solving simultaneous equations by elimination. Target a variable to eliminate. Solve two linear simultaneous equations in two variables in very simple cases (no multiplication required). Plot and interpret distance-time graphs (speed-time graphs). Find approximate solutions to kinematic problems involving distance and speed. Use the form y = mx + c to identify parallel lines. Rearrange an equation into the form y = mx + c. Find the equation of a line through one point with a given gradient. Find the equation of a line through two given points. Interpret the gradient of a straight line graph as a rate of change. Explain why the base angles in an isosceles triangle must be equal Explain the connections between Pythagorean triples.

3 Interpret a wider range of non-standard graphs and charts. Understand that correlation does not indicate causation. Interpret a scatter diagram using understanding of correlation. Find the midpoint of a class. Calculate an estimate of the mean from a grouped frequency table. Estimate the range from a grouped frequency table. Choose appropriate statistics to describe a set of data. Justify choice of statistics to describe a set of data. List outcomes of combined events using a tree diagram. Label a tree diagram with probabilities. Know when to add/multiply two or more probabilities. Use a tree diagram to calculate probabilities of independent/dependent combined events. Understand that relative frequency tends towards theoretical probability as sample size increases.

4 Meeting 5 Interpret a large (small) number written in standard form. Use a calculator to evaluate numerical expressions involving powers (roots). Use a scientific calculator to calculate with fractions, both positive and negative. Use ruler and compasses to construct the perpendicular bisector of a line segment. Use ruler and compasses to bisect an angle. Use a ruler and compasses to construct a perpendicular to a line from a point (at a point). Understand the meaning of locus (loci). Know how to construct the locus of points a fixed distance from a point (from a line). Identify when to use the locus of points a fixed distance from a point (from a line). Know the multiplication (division, power, zero) law of indices. Understand that negative powers can arise. Know the meaning of the subject of a formula. Change the subject of a formula when one step is required. Solve problems involving percentage change. Solve original value problems when working with percentages. Know the formula for finding the volume of a right prism (cylinder) Calculate the volume of a right prism (cylinder). Recognise the Fibonacci sequence. Generate Fibonacci type sequences. Find the next three terms in any Fibonacci type sequence. Recognise a simple linear inequality. Find the set of integers that are solutions to an inequality. Use set notation to list a set of integers. Use a formal method to solve an inequality. Know how to show a range of values that solve an inequality on a number line. Know when to use an open circle at the end of a range of values shown on a number line. Know when to use a filled circle at the end of a range of values shown on a number line. Find a relevant multiplier in a situation involving proportion. Plot the graph of a linear function. Understand that there are an infinite number of solutions to the equation ax + by = c Distinguish between a linear and quadratic graph. Plot graphs of quadratic functions of the form y = x 2 + c Construct a line of best fit on a scatter diagram. Use a line of best fit to estimate values. Know when it is appropriate to use a line of best fit to estimate values. Calculate the mean from a frequency table Find the mode from a frequency table. Find the median from a frequency table. Understand the range as a measure of spread (or consistency). Calculate the range of a set of data. Analyse and compare sets of data. Appreciate the limitations of different statistics (mean, median, mode, range). Find the modal class of set of grouped data. Find the class containing the median of a set of data. List all elements in a combination of sets using a Venn diagram. List outcomes of an event systematically. Use a table to list all outcomes of an event. List outcomes of an event using a grid (two-way table) Use frequency trees to record outcomes of probability experiments

5 Make conclusions about probabilities based on frequency trees Construct theoretical possibility spaces for combined experiments with equally likely outcomes. Calculate probabilities using a possibility space. Use theoretical/experimental probability to calculate expected outcomes. Developing 4 Write a large (small) number in standard form. Know the multiplication and division laws of indices. Identify fluently angles at a point, angles at a point on a line and vertically opposite angles. Identify known angle facts in more complex geometrical diagrams. Use knowledge of angles to calculate missing angles in geometrical diagrams. Know that angles in a triangles total 180. Find missing angles in triangles. Use compasses to construct clean arcs. Create and interpret scale diagrams. Identify the multiplier for a percentage increase or decrease when the percentage is greater than 100%. Use calculators to increase an amount by a percentage greater than 100%. Use calculators to increase (decrease) an amount by a percentage using multiplicative methods. Know that percentage change = actual change original amount. Know and use the formula for area and circumference of a circle. Know how to use formulae to find the area of rectangles, parallelograms, triangles and trapezia. Know how to find the area of compound shapes. Generate a linear sequence from its nth term. Substitute positive numbers into quadratic expressions. Find the nth term for an increasing linear sequence. Find the nth term for a decreasing linear sequence. Understand the meaning of a compound unit. Convert between units of length, capacity, mass and time. Recognise graphs of simple quadratic functions. Plot and interpret graphs of kinematic problems involving distance and speed. Know the criteria for triangles to be congruent (SSS, SAS, ASA, RHS) Identify congruent triangles. Construct graphs of time series. Interpret graphs of time series. Construct and interpret compound bar charts. Find the median of a set of data when there are an even number of numbers in the data set. Use the mean to find a missing number in a set of data. Recognise when it is not possible to work out a theoretical probability for an event. Know that the sum of probabilities for all outcomes is 1. Apply the fact that the sum of probabilities for all outcomes is 1. Em ergi 3 Approximate by rounding to the first significant figure in any number. Round to a given number of decimal places or significant figures. Know the meaning of the symbols <, >,,. Apply the four

6 operations with fractions and mixed numbers. Convert between an improper fraction and a mixed number. Explore enlargement of 2D shapes. Use and interpret scale drawings. Use and interpret bearings. Explore ways of representing 3D shapes. Know standard mathematical constructions. Apply standard mathematical constructions. Understand the concept of an enlargement (no scale factor). Manipulate expressions by collecting like terms. Know that x x=x 2 Know the difference between an expression, an equation and a formula. Know the meaning of discrete and continuous data. Interpret and construct frequency tables. Construct and interpret pictograms, bar charts, pie charts, tables, vertical line charts, histograms (equal class widths) and scatter diagrams. Calculate the mean of a set of data. Find the mode and the median of set of data. Understand the equivalence between fractions, decimals and percentages. Compare fractions, decimals or percentages. Simplify a fraction by cancelling common factors. Add fractions (decimals). Multiply fractions (decimals). List all the outcomes for an experiment. Identify equally likely outcomes. Work out theoretical probabilities for events with equally likely outcomes. Know how to represent a probability. 1/2 Know the meaning of a prime number. Recall prime numbers up to 50. Understand the use of notation for powers. Know how to round to the nearest whole number, 10, 100, 1000 and to decimal places. Multiply and divide numbers by powers of 10. Know how to identify the first significant figure in any number. Know the meaning of powers. Know the meaning of roots. Use a protractor to measure angles to the nearest degree. Use a ruler to measure lengths to the nearest millimetre. Understand coordinates in all four quadrants. Work out a multiplier given two numbers. Use compasses to draw circles. Calculate with negative numbers. Know the grid method for multiplying two two-digit numbers. Know angle facts including angles at a point, on a line and in a triangle. Know that probability is a way of measuring likeliness. Know and use the vocabulary of probability. Understand the use of the 0-1 scale to measure probability. Assess likeliness and place events on a probability scale.