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WS03 - Fencing in the Vegetable Patch

Mathematics, Year 9

By the end of Year 9, students recognise and use rational and irrational numbers to solve problems. They extend and apply the exponent laws with positive integers to variables. Students expand binomial products, and factorise monic quadratic expressions. They find the distance between 2 points on the Cartesian plane, and the gradient and midpoint of a line segment. Students use mathematical modelling to solve problems involving change in financial and other applied contexts, choosing to use linear and quadratic functions. They graph quadratic functions and solve monic quadratic equations with integer roots algebraically. Students describe the effects of variation of parameters on functions and relations, using digital tools, and make connections between their graphical and algebraic representations.

 

They apply formulas to solve problems involving the surface area and volume of right prisms and cylinders. Students solve problems involving ratio, similarity and scale in two-dimensional situations. They determine percentage errors in measurements. Students apply Pythagoras’ theorem and use trigonometric ratios to solve problems involving right-angled triangles. They use mathematical modelling to solve practical problems involving direct proportion, ratio and scale, evaluating the model and communicating their methods and findings. Students express small and large numbers in scientific notation. They apply the enlargement transformation to images of shapes and objects, and interpret results. Students design, use and test algorithms based on geometric constructions or theorems.

 

They compare and analyse the distributions of multiple numerical data sets, choose representations, describe features of these data sets using summary statistics and the shape of distributions, and consider the effect of outliers. Students explain how sampling techniques and representation can be used to support or question conclusions or to promote a point of view. They determine sets of outcomes for compound events and represent these in various ways. Students assign probabilities to the outcomes of compound events. They design and conduct experiments or simulations for combined events using digital tools.

Algebra

AC9M9A02

simplify algebraic expressions, expand binomial products and factorise monic quadratic expressions

Algebra

AC9M9A04

identify and graph quadratic functions, solve quadratic equations graphically and numerically, and solve monic quadratic equations with integer roots algebraically, using graphing software and digital tools as appropriate

Algebra

AC9M9A05

use mathematical modelling to solve applied problems involving change including financial contexts; formulate problems, choosing to use either linear or quadratic functions; interpret solutions in terms of the situation; evaluate the model and report methods and findings


Annotations

 

1. Provides labelled diagrams and reasoning to demonstrate how the length of the shed and doorway determine the dimensions of the rectangular shape.

 

2. Extends previous results to determine additional values for length and corresponding values for area.

3. Sets up scaled and labelled axes, and plots values from the table.

 

4. Recognises other values for width by joining plotted coordinates.

5. Identifies the shape of the graph as a parabola from which a maximum value can be determined.

 

6. Connects the graph of a parabola to its algebraic representation of a quadratic function.

 

7. Manipulates algebraic expressions for length and area and explains how the area can be expressed as a quadratic function.