calculators in schools important to spend time building non-calculator skills. should schools have a...

Calculators in schools•Important to spend time building non-calculator skills. Should schools have a dedicated non-calculator exam ?

•They aren’t going away => we need an intelligent way of dealing with them.

•Pupils will have different makes of calculator => we, as teachers should be able to master most popular types of calculator.

•School Policy on calculators: Each school should decide how to integrate the use of calculators into their school.Calculators in first year ? No calculators until Christmas of first year ?One particular type of calculator recommended by a school ?

•Golden rule: Don’t do anything on the calculator that you haven’t already written on paper

Using the fraction capability

Example : Evaluate ¾ + ½

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Example : Evaluate 2¾ + ¼ Right arrow arrow

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Using the memory capability

Example : Store 6.8 in memory location X

Example : Evaluate 0.2 + X using the memory function

Task : 1) Store 3.8 in memory location Y

2) Use the memory function to evaluate X + Y

3) Change the numbers in memory X to 4 and memory Y to 5 and then evaluate X + Y, using the memory function

4) Evaluate 5X2 – 7x -1

5) Evaluate 4X3 +2X2 –x +4

Clearing all settings on the calculator

Recommended decimal setting

All Yes Re-set

Norm

Trigonometry and the calculator

1) To make sure that the calculator is in degree mode

2) To find sin 60º

3) To find 1 1sin

2

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4) Changing the calculator to radian mode

5) To find tan 3

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6) To find tan-1 1

3

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Converting degrees to radians and radians to degrees

N.B. Your calculator should be in the mode of the targeti.e. in degrees if changing from radians to degrees and in radians if changing from degrees to radians

Example 1 Change 60º to radians a) Make sure the the calculator is in radian mode

b) Then do the conversion

Example 2 Change radians to degrees4

a) Make sure the the calculator is in degree mode

b) Then do the conversion

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Graph the function y=x2+3x-4 in the domain -5x2

Step 1: Go into table mode in calculator

Step 2: Set up function

Step 3: To set up lowest x co-ordinate

Step 4: To set up highest x co-ordinate

Step 5: To see table

Graph the function y=x2+3x-4 in the domain -5x2

Handout

Recommended calculator use for functions

Graph the function y=x2+3x-4 in the domain -5x2

f(x) = x2 + 3x -4

f(-5) = (-5)2 + 3(-5) -4 = 6 (-5, 6)

f(-4) = (-4)2 + 3(-4) -4 = 0 (-4, 0)

f(-3) = (-3)2 + 3(-3) -4 = -4 (-3, -4)

f(-2) = (-2)2 + 3(-2) -4 = -6 (-2, -6)

f(-1) = (-1)2 + 3(-1) -4 = -6 (-1, -6)

f(0) = (0)2 + 3(0) -4 = -4 (0, -6)

f(1) = (1)2 + 3(1) -4 = -4 (1, -4)

f(2) = (2)2 + 3(2) -4 = 6 (2, 6)

Scientific NotationNumbers in scientific format can be added, subtracted, multiplied and divided without changing the calculator into scientific mode. The only drawback is that if a number is small enough to display as a natural number it will be shown as a natural number. e.g. (3.2 x 103) x (1.7 x 105) = 544 000 000

If you want this number converted to scientific notation you must change the calculator into scientific notation mode

Getting into scientific notation mode:

Getting out of scientific notation mode:

Changing Cartesian coordinates to polar form

a) Calculator better in degree mode for this

b) Then do the conversionRight arrow arrow

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Example Change 2 , 2 to polar form

TASKS

Try the following functions using the table mode

1) y = 3x -2 in the domain -3 x 3

2) Graph the function f: x 7-5x-2x2 in the domain -4 x 2

3) Graph the function

TASKS:

1) Store 5 in memory and then use the memory recall function to evaluate 2x3-6x2+4x-9 when x is 5 ( Answer is 111 )

2) Evaluate (43)2 and also evaluate 729 1/6 ( Answers are 4096 and 3 )

3) 6.4 x 107 – 1.2 x 105 (Answer is 63 880 000)

4) Demonstrate the following limit

1: in the domain -4 x 1 , x -2

x+2f x

0

lim

Sin