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Using Graphical Calculators in the Classroom. Richard Tarry Sept 2004. Setting up the calculator. If necessary insert the 2 batteries supplied After you have inserted the batteries, pull out the protection strip
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Using Graphical Calculators in the Classroom Richard Tarry Sept 2004
Setting up the calculator • If necessary insert the 2 batteries supplied • After you have inserted the batteries, pull out the protection strip • All users – reset the calculator by pressing a pen into the little hole above the battery compartment • Press YES (F1) below the screen, then press MENU
Getting Started • Press AC/ON to switch on • The calculator uses a menu system • Let’s go into GRAPH • Either press the menu number (4) or navigate with the cursor to the GRPH icon and push EXE • Push MENU to get back to the home screen • Press QUIT to return to an earlier screen
Using RUN mode • Reset the calculator by pressing a pen into the little hole above the battery compartment • Press YES (F1) below the screen, then press MENU
SET UP for RUN • Enter RUN • Enter SET UP • Use the cursor and the function keys to set Angle to Deg(rees) • Use QUIT to return to a blank screen • This is the most common setup change!
RUN Mode RUN mode features • On-screen display – algebraic order • You should use brackets • You can work with fractions • You can edit (before and after AC) • Ans stores the last answer • You can store results in ALPHA memories
Learning the keys • EXEcute is like = it gives the answer • Find out how to add, subtract, multiply, divide, square, square root, raise to a power (such as 53), find sine & cosine • Find out the difference between the – and (-) keys • Find out what SHIFT and ALPHA do • Find out how you can use the cursor to edit a calculation • Find out how to use DELete & INSert • Clear the screen
4.1 x 3.8 6.5 0.175 … then edit to 6.5 0.185 sin30 + cos45 40 + 20 …. then edit to 4.4 + 2.1 (2.35 + 1.82) 0.9 4.15 (-2.5)3 3.5x108 X 7 000 000 16 π Answers are on the next slide Some easy calculations Do the following calculations and write down your answers to 3 sf.
Answers (all to 3 sf) • 15.6 • 37.1, 35.1 • 1.21 • 10.8, 3.55 • 4.63 • -74.1 • 2.45 x 1015 • 50.3
Variables & Memories • Results of calculations are stored automatically and manually • Ans automatically stores the last answer • X,T is an easy access storage and also acts as the variable x • The stores a value into a memory • A, B, C, D, …. Z are all memories
Using variables and memories – the Ans key • Calculate 2 x 1.4 • Then type – 1 EXE and explain what has happened • Now calculate 3 x 1.4 , followed by 5 – Ans. • Now type 2 x Ans. • Describe in your notes how ANS can be used
Using the X,T key and replay • Clear the screen • Type 2 X EXE, then 3x2 –5x + 12 EXE. Check the answer and explain what the calculator has done. • Now type 5 X EXE, and then clear the screen with AC/ON • Press the cursor twice – you should now see 3x2 –5x + 12 on the screen • Press EXE • Explain the result.
In your groups, find and write down the following formulas… • Gradient of a straight line • Pythagoras • Area of a circle • Volume of a cylinder • The quadratic formula • Distance between 2 points
Finding a gradient… • Write down the gradient formula • Write down a mathematical expression to find the gradient of the line joining the points (2,5) and (10,41) • Use the brackets function of the calculator to find the gradient in one go
More gradients… • You should have typed (41-5)÷(10-2) EXE and obtained a gradient of 4.5 • Now find the gradient of the line joining (-3,15) to (17,-35) Challenge:Find the equation of each line.
Volume of a cylinder • Write down the volume formula • Write down a mathematical expression to find the volume of a cylinder with radius 6.5 cm and height 13cm. • Use the π key and find this volume • You should get an answer of 1726 cm3
More volume calculations… • Find the volume of a cylinder with radius 2.5cm and height 18 cm. • Rearrange the formula to make height the subject • Write down a mathematical expression (using brackets) to find the height of a cylinder of capacity 500 ml, and radius 5.5cm • Find the height correct to 1 dp.
Volumes … • You should have written h=500÷(πx5.52) EXE and got an answer of 5.3cm • What height is a cylinder holding 1 litre, with radius 7.5cm? Challenge: • Make radius the subject • Write down a mathematical expression to find the radius of a cylinder holding 600 ml of height 11cm • Now find the radius (in one go!)
The quadratic formula.. • Use the quadratic formula to solve 3x2 + 5x – 17 = 0. Save both answers. • Remember to use brackets! • Use the edit function to get the 2nd solution by changing a plus to a minus. You should get answers of -3.36 and 1.69 You should have typed (-5+(52-4x3x-17))(2x3) EXE but there are other methods using a memory rather than a single calculation
Generating a sequence • Write down the first 4 terms of the sequence un+1 = 1.05Un – 20with u0 = 1500 • First type 1500 EXE (This stores 1500 in Ans) • Type 1.05Ans-20 EXE • Press EXE again, and again…Describe a situation that this sequence could model. • You should get answers 1555, 1612.75, 1673…, 1737…
Challenge… From an AS Using Maths paper Tw = 33 – (33 – T)[0.47 + 0.3v – 0.02v] • Tw is windchill temperature (oC) • T is temperature out of the wind (oC) • V is the wind speed (mph)
Harder problems… • Find the windchill temperature if the temperature out of the wind is 8oC… when the wind is blowing at 5 mph. • What is the temperature if the wind speed increases 4 times. • One day the temperature out of the wind was 10oC, but in the wind it was 2oC. What was the wind speed?
Using the Statistics mode • Reset the calculator by pressing a pen into the little hole above the battery compartment • Press YES (F1) below the screen, then press MENU
STAT mode • Enter STAT • Data can be stored in Lists 1 – 6 • You can navigate around the lists with the cursor • You can simply overtype existing data or delete an entire list
Entering data Enter the following data into List 1 • 10, 9, 9, 12, 15 • You need to push EXE after each number • The top row of function keys are used in conjunction with the screen
Deleting and inserting data • Use in the top row just below the screen to obtain DEL, DEL-A, INS • Move the cursor onto the 12 in the list, press F1 (DEL) – what happens? • Now press F3 (INS) – what happens? • Overtype the 0 with 8. • Move the cursor to any position in List 1. Then press F2 (DEL-A). What happens? Press F1 (YES).
Working with some data • Enter the following data into List 1 : 10, 8, 9, 12, 15, 8, 3, 17 • Press CALC (F2 ), then 1 VAR (F1) • Use the cursor to scroll down • Check that n=8 (this this a good way to check you haven’t missed any data) • Write down the mean and standard deviation, and the median and quartiles (Q1 & Q3). • What is the range of the data? • Press QUIT when you have finished
Statistical graphs • Press GRPH (F1 ) • Useto obtain SEL(ect) & SET • Press SET (F4 ) • Use the cursor to move down the settings list • Notice how a new set of choices appears at the bottom of the screen for each setting
Set up some graphs Set up StatGraph1 with • G-Type : Pie • Data : List1 • Display : Data Set up StatGraph2 with • G-Type : Box (you will need to use ) • XList : List1 • Freq : 1 Now press QUIT
Draw your statistical graphs and use Trace (F1) • Press GRPH (F1), then GPH1 • QUIT and press GRPH then GPH2 • Now press SHIFT followed by Trace • Use the horizontal cursor to locate points on the box chart • Sketch the box chart labelling the 5 points that Trace shows you. • Use GT to return to the statistics screen and then QUIT • Explain what the box plot shows.
Analysing grouped data • Delete any previous data • Enter data oppositeinto Lists 1 & 2 • Discuss in your group what this data means
Set up the calculator • The SET function assigns statistical variables to your data lists – enter CALC & press SET • Assign List1 to 1Var X and List2 to 1Var F (Discuss what this means – why not 2Var?) • QUIT to return to the List screen • Enter CALC, 1VAR and scroll down the results
Analysis of the data Write down the answers to all these questions and make sure you understand them – check if possible. • Find the number of students who were surveyed • Find the mean age • Find the median age & the quartiles • Make a boxplot & copy it – show the position of the mean on your sketch • QUIT
Another problem –this time with two variables The data is on the next slide • Enter the data in List 1 (Age) & List 2 (Height) • Use CALC and SET to to set up 2Var X: List12Var Y: List22Var F: 1 • QUIT, press CALC and 2VAR
Questions… • What is the mean age of the children? • What is their mean height? • Press REG, then F1 (X) • Copy down the values for a, b, r and write down the equation. • Substitute a & b into the equation and discuss what it means.
Further analysis… • Press GRPH thenthen SET • Set up StatGraph1 to draw a scattergram with Xlist set to List1, Ylist set to List2, Freq as 1 • QUIT and use GRPH to draw the scattergram • Press x – what do you notice? • Then press DRAW. Copy what you see and relate it to your equation.
Here’s some more data to add to your lists Draw a scattergram but this time choose x^2 Write down the equation Compare the x and x^2 graphs and explain what this shows Advanced analysis
Useful tips • If you want to clear the screen, press SHIFT, Sketch, then Cls (F1 ) – the last graph only will be redrawn • After you have drawn a graph, press GT to return to the screen showing data • You can COPY the equation into the Graph Functions list for later use
Using the Graphs mode • Reset the calculator by pressing a pen into the little hole above the battery compartment • Press YES (F1) below the screen, then press MENU
Working with Graphs • From the menu, enter the GRPH mode • Type 2X+3 (use the X,T key) next to Y1 then EXE • Press EXE again (or DRAW) • Use Zoom (F2) OUT to display both intercepts • Use Trace (SHIFT F1) to find the coordinates of the intercepts • Make a rough sketch of the graph labelling the intercepts
Adjusting the view • Press GT a few times and see what happens. • Press SHIFT F3 to obtain the V(iew) Window. • Use the cursor to move down the settings – discuss what they all do. • Reset to Xmin to (-)4, max to 4, Ymin to (-)2, max to 6. You need to use EXE to store each setting you change. • Redraw the graph.
Investigating graphs • Press GT to return to the Graph Function screen • At Y2 type in 5 – X and draw the graphs • Adjust the View to show all intercepts – add the new graph to your sketch
Using the Trace to solve equations simultaneously • Press Trace (SHIFT F1) • Use the left-right cursor to move along a graph • The up-down cursor enables you to jump to the other graph • Find the coordinates of the intersection as accurately as you can • Now use Zoom and Trace to improve your accuracy – write down your answer to 3 dp.
Check with algebra • Here are the two equations again y = 2x + 3 and y = 5 – x • Solve them algebraically in your groups. • Compare your answers to what you got for the graphical solution.
Moving on … Quadratic transformations • Delete all previous graph functions • Draw Y1= X2 and set the View to INIT(ial) • Draw Y2= (X–3)2 and Y3= (X+2)2 • Return to the Graph Functions - investigate how to select and deselect functions. • Make a labelled sketch showing all 3 graphs, their equations and x-intercepts.