2.54 To calculate by selecting operations appropriate to solving

Mathematics

Common and decimal fractions

Common fractions

Educator section

Memorandum

INTRODUCTION

The learning programme for grade six consists of five modules:

1. Number concept, Addition and Subtraction

2. Multiplication and Division

3. Fractions and Decimal fractions

4. Measurement and Time

5. Geometry; Data handling and Probability

• It is important that educators complete the modules in the above sequence, as the learners will require the knowledge and skills acquired through a previous module to be able to do the work in any subsequent module.

COMMON AND DECIMAL FRACTIONS (LO 1; 2 AND 5)

LEARNING UNIT 1 FOCUSES ON COMMON FRACTIONS

• This module continues the work dealt with in grade 5. Addition and subtraction of fractions are extended and calculation of a fraction of a particular amount is revised.
• Check whether the learners know the correct terminology and are able to use the correct strategies for doing the above correctly.
• Critical outcome 5 (Communicating effectively by using visual, symbolic and /or language skills in a variety of ways) is addressed.
• It should be possible to work through the module in 3 weeks.
• ** Activity 17 is designed as a portfolio task. It is a very simple task, but learners should do it neatly and accurately. They must be informed in advance of how the educator will be assessing the work.

• LEARNING UNIT 2 FOCUSES ON DECIMAL FRACTIONS
• This module extends the work that was done in grade 5. Learners should be able to do rounding of decimal fractions to the nearest tenth, hundredth and thousandth. Emphasise the use of the correct method (vertical) for addition and subtraction. Also spend sufficient time on the multiplication and division of decimal fractions.
• As learners usually have difficulty with the latter, you could allow 3 to 4 weeks for this section of the work.

** Activity 19 is a task for the portfolio. The assignment is fairly simple, but learners should complete it neatly and accurately. They must be informed in advance of how the educator will be assessing the work.

1. 165,2 ℓ

2. 372,564

3. 56,42 kg

4. 147,431 m

5. and 6. Own explanation

Leaner section

Content

Activity: to calculate by selecting operations appropriate to solving problems [lo 1.8.8]

You have to work in groups of three for the following activity. Ask the educator for the paper that you will need. Read through the problems attentively and try to find the answers. Remember to show the operations that you use!

1. Mr Katlego has had to put petrol into his minibus on three occasions this month, to transport passengers. He first put in 59,81 litres, then 48,65 litres and finally another 56,75 litres. How many litres of petrol have been put into his minibus this month?

2. What is the difference between 900 and 527,436?

3. Didi was very overweight and decided to take action. Before dieting, she weighed 143,21 kg. After a few months she weighed 86,79 kg. How many kg has Didi lost?

4. Mr Naidoo has decided to take his class to the game park. The following interesting information was derived from this visit:

If you stacked all these animals on top of one another, how high would they be?

5. Explain to the rest of the class how your group calculated the answers.

6. Compare your methods. How do they differ from one another?

TIME FOR SELF-ASSESSMENT

Assess your work on a scale of 1 - 4 by circling the appropriate number:

1 = not at all

2 = just a little

3 = good

4 = outstanding

DO YOU REMEMBER THIS?

When we add and subtract decimal fractions, we could write the numbers below one another and add or subtract normally. The commas, however, have to be exactly in line to ensure that the answer is correct.

E.g. x = 19,046 + 3,49 + 127,6

1 9 , 0 4 6

3 , 4 9

+ 1 2 7 , 6

1 4 0 , 1 3 6

Assessment

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 1.8: We know this when the learner estimates and calculates by selecting and using operations appropriate to solving problems that involve:

1.8.8 addition and subtraction of positive decimals with at least 2 decimal places.