3.3 and 3.4 y


12 11 10


1 2 3 4 5 6 7 8 9


0 12 34 5


Unit 6 Integers Unit focus


• revise the additive and multiplicative inverses of integers.


Background information In previous grades, the learners learnt to: • do calculations involving all four operations with integers; • do calculations involving all four operations with numbers that involve the squares, cubes, square roots and cube roots of integers;


• recognise and use commutative, associative and distributive properties of addition and multiplication of integers; and


• recognise and use additive and multiplicative inverses for integers. Exercise 1


Guidelines on how to implement this activity


Revise the number line for integers by drawing such a number line on the board and ask questions to find out what the learners still remember about integers and the properties of integers.


Suggested answers 1.1


7 + ( −4 ) = 3


1.3 −7 + ( −4 ) = −11 7 + ( −10 ) = −3


1.5


1.2 −7 + 4 = −3 1.4 12 + ( −12 ) = 0 1.6 0 + ( −17 ) = −17


Chapter 1: Numbers and integers 43 Learner’s Book page 35 6 7


• From the table in 3b above one can see that the variable b increases when the variable l decreases and that the variable b decreases when the variable l increases. This is also shown by the graph you drew in 3d.


• In general: x and y are indirectly proportional if, as the value of x increases the value of y decreases, and as the value of x decreases the value of y increases.


x 8 9 10 11 12


Learner’s Book page 35


This unit focusses on the following: • revise calculations with integers; • revise the use of the commutative, associative and distributive properties of addition and multiplication for integers; and


CHAPTER 1


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