Using Probing Questions in Mathematics lessons What do you think? Year 8 Level 6 Assessment Criteria Click on a link to Jump to the Assessment Criteria you are looking for. Assessment Criteria for Year 8 Level 6 • Using and applying mathematics to solve problems • Numbers and the number system • Calculations • Algebra • Shape, space and measures • Handling data Using and applying mathematics to solve problems • Use logical argument to establish the truth of a statement. How do you know that expression matches the pattern? Well, it works for the 3rd arrangement. Which pattern? The red squares or the white squares, or both? What if I make a different pattern? Numbers and The Number System • Use the equivalence of fractions, decimals and percentages to compare proportions; calculate percentages and find the outcome of a given percentage increase or decrease. • Divide a quantity into two or more parts in a given ratio; use the unitary method to solve simple word problems involving ratio and direct proportion. Well, from that I can work out lots of other equivalents I know that: 1 0.1 10% 10 I notice a link between sets of fractions, decimals and percentages. I bet you can’t work them out for one third! Which fraction is it closer to? What about 20 ? 61 I can find a fraction between 1 and 1 3 2 How do you do it? I don’t think you can find out exactly how many students there are. The ratio of students with mp3 players to those without is 3:1 I wonder if there could be 30 students. I bet there’s 25 boys. Algebra • Plot the graphs of linear functions, where y is given explicitly in terms of x; recognise that equations of the form y = mx + c correspond to straight-line graphs. I have trouble deciding on what scale to use. I need to graph y = 2x + 4. I wonder how I could get a set of points to plot. Don’t you just put 2 on the x-axis and 4 on the yaxis, then join that up? I know we need an x and y axis, but I can never figure out how big to make the graph. I have to draw y = 3x + 5. I wonder if it’s steeper. I need to graph y = 2x + 4. I wonder how I could do it without this computer. If one number is the gradient, what’s the other number for? I can never remember which number affects the gradient. Shape, Space and Measures • Identify alternate and corresponding angles; understand a proof that the sum of the angles of a triangle is 180° and of a quadrilateral is 360°. • Classify quadrilaterals by their geometric properties. • Enlarge 2-D shapes, given a centre of enlargement and a positive whole-number scale factor. • Use straight edge and compasses to do standard constructions. • Deduce and use formulae for the area of a triangle and parallelogram, and the volume of a cuboid; calculate volumes and surface areas of cuboids. This should help us to find out the sum of angles of a quadrilateral. Should we use something like corresponding and alternate angles? How do I convince someone that the sum of the angles in a triangle is 180o? Don’t you have to draw in some parallel lines somewhere? I think that kind of trapezium would have three acute angles. I don’t think you can get any quadrilaterals with three acute angles. I think I can draw an isosceles trapezium. Wouldn’t that be just a parallelogram ? I notice that when you enlarge a shape, some things change and some stay the same. I wonder what the scale factor is. I want to find the centre of enlargement. How do we know if the shape is being enlarged or…umm shrunk? Why do we need to use compasses anyway? I think bisecting the angles of a rhombus would be easy. I can never remember when I should keep the same compass arc. I think the formula for the area of a triangle is related to the formula for the area of a parallelogram. I know there’s a formulas for a triangle. I wonder if there is a formula for the area of every 2D shape? AREA = 12 cm2 I think I can work out the dimensions of this triangle. It’s hard to find the area of some types of triangles, but others are really easy. Handling data • Construct, on paper and using ICT; – pie charts for categorical data; – bar charts and frequency diagrams for discrete and continuous data; – simple time graphs for time series; – simple scatter graphs. Identify which are most useful in the context of the problem. • Find and record all possible mutually exclusive outcomes for single events and two successive events in a systematic way. I wonder if showing our results in a graph would be most useful to show the answer to this hypothesis? I think we need to group the data. What class intervals should we use? Hypothesis: The older you are, the more television you watch. I think I want to use the graph which is the easiest to interpret. I think we should use the type of graph that is the most helpful. I want to make a pie chart how can we work out the angles again? Height of Seedling (cm) Frequency 0 – 4.9 3 5.0 – 9.9 8 10.0 – 14.9 15 15.0 – 19.9 6 I’m not sure if we should draw a pie chart. This is continuous data, isn’t it? Are those class intervals OK. They don’t look quite right. I wonder how many different outcomes there are? Rule: Spin and Add the numbers How do you know if you have all the possibilities? I think we have to find all possible outcomes, whether they are different or not. What’s the best way of recording all the possible outcomes? Thanks to Emile Pinco, Head of Mathematics at Churchdown School, for compiling this resource Based on material from the Secondary Strategy’s ‘Focused Assessment Materials’ (APP) and ‘Progression Maps’ Some images from www.stfx.ca