m21785 Fun with the pocket calculator 1.1 2009/04/14 13:50:22.110 GMT-5 2009/04/14 13:54:03.322 GMT-5 Helen Saayman Helen Saayman mark.horner@shuttleworthfoundation.org Helen Saayman Helen Saayman mark.horner@shuttleworthfoundation.org Helen Saayman Helen Saayman mark.horner@shuttleworthfoundation.org Mathematics and Statistics en

6. a) get dressed and eat clean different rooms in the house order in which you do your homework learners gives own answers first draw money and then do your shopping fisrt learn your work and then write a test cover books; plastic last throw petrol in first and then ride learners give own answers 8. a) 66 0 9 223 153

6 SEQUENCE OF CALCULATIONS If you do not know the sequence in which you have to do calculations, the pocket calculator will not be of any help to you - it will actually help you out of the frying pan into the fire! Discuss the following: a) Does it matter if you put the milk into the teacup before pouring the tea, or the tea before the milk? b) Do you brush your teeth before breakfast or do you eat first and then brush your teeth? c) Give examples of where the sequence in which you do things does not matter. d) Give examples of where the sequence matters/is important. 7 MORE REVISION We work from left to right when we do repeated addition and subtraction. e.g. 20 – 5 + 12 – 5 – 2 = 20 We work from left to right for repeated multiplication and division. e.g. 6 × 3 ÷ 2 = 9 In the case of mixed calculations, the sequence is: ( ) brackets of ÷ × + -

8. Use your pocket calculator to find the answers to the following: a) 100 – 4 × 5 – half of 28 ______________________________________________________________ b) 26 × 54 – 54 × 26 ______________________________________________________________c) 200 ÷ 20 + 285 ÷ 95 – 8 + 4 ______________________________________________________________d) 382 – (129 + 31) + one third of 3 ______________________________________________________________ e) (65 – 15) × 3 + 21 ÷ 7 ______________________________________________________________

Learning Outcome 1:The learner will be able to recognise, describe and represent numbers and their relationships, and to count, estimate, calculate and check with competence and confidence in solving problems. Assessment Standard 1.9: We know this when the learner uses a range of techniques to perform calculations including: 1.9.2: using a calculator.