1.18 Negative numbers (number line)

Mathematics

Having fun with pocket calculators and negative numbers

Educator section

Memorandum

19.1 a) -7

1. 4
2. -3
3. 4
4. -5

19.2 a) -10

1. -2
2. -4
3. –5
4. 19.3 a) -33; -26; 20; 48; 179

1. -3 000; -300; -30; -3; 3
2. -598; -387; -68; 0; 479; 1 009

19.4 7; -14; -37; 14; -25

17; -22; -38; 21; -56

Leaner section

Content

Activity: negative numbers (number line) [lo 1.3, lo 2.1]

18. DID YOU KNOW?

There were many mathematicians who did not like negative numbers. Diophantus, who was a Greek mathematician, thought it was “absurd”. Another mathematician, Stifel, thought the idea of negative numbers was “ridiculous”!

numbers become bigger19. Let us take a look at negative numbers on a number line:

numbers become smaller

19.1 Work with a friend and indicate which number is:

a) 2 smaller than –5 ____________________

b) 7 bigger than –3 _____________________

c) 5 bigger than –8 _____________________

d) 9 smaller than 5 _____________________

e) 8 smaller than 3 _____________________

19.2 Circle the smallest number:

a) -10 of -6

b) 2 of -2

c) -4 of 0

d) -1 of -5

19.3 Arrange the following numbers from small to large:

a) 20 ; 48 ; -26 ; -33 ; 179

_____________________________________________________________________

b) -30 ; 3 ; -300 ; -3 ; - 3 000

_____________________________________________________________________

c) 479 ; 0 ; -598 ; -387 ; 1 009 ; -68

_____________________________________________________________________

19.4 Calculate the output numbers in the flow diagram:

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 1.3: We know this when the learner recognises, classifies and represents the following numbers in order to describe and compare them.

Learning Outcome 2: The learner will be able to recognise, describe and represent patterns and relationships, as well as to solve problems using algebraic language and skills.

Assessment Standard 2.1: We know this when the learner investigates and expands numeric and geometric patterns looking for a relationship or rules, including patterns.