1.3 Number patterns (mental calculations)

Mathematics

Number patterns

Educator section

Memorandum

7.

a) 96

b) 61

c) 53

d) 13

e) 12

f) 54

g) 82

h) 24

i) 80

j) 178

k) 2 700

l) R90

m) R60,80

n) 24 000

o) 90

p) R237

q)

r)

s)

t) 34.25

• increases with one (+1)
• increases with 7 (+7)
• increases with 8 (+8)

8.4 increases with 6 (+6)

• 6; 27; 48
• 24; 27; 30

The total is different

• 27; 27

8.5.4 The total is the same

it is the same as above

Leaner section

Content

Activity 1: number patterns (mental calculations) [lo 2.2]

• Let us see how you cope with the following mental calculations. Try and complete the test in less than two minutes.

a) 12 × 8 = _________________

b) 23 + 38 = _________________

c) 48 + _________________ = 61

d) 132 ÷ _________________ = 11

e) 71 – 18 = _________________

f) _________________ ÷ 6 = 9

g) 63 + 19 = _________________

h) 39 + . _________________ = 63

i) 7 × _________________ = 560

j) Double 89: _________________

k) 90 × 30 = _________________

l) R4,50 × 20 = _________________

m) 400 × 60 = _________________

n) 2 700 ÷ . _________________ = 30

o) R6,08 × 10 = _________________

p) R2,37 × 100 = _________________

q) 3/8 of 64 = _________________

r) 4/5 of 45 = _________________

s) 6/7 of 42 = _________________

t) Halve 68,5: _________________

I have . ________________________________________. correct.

• Colour in the face that shows how you feel:

8 . Look at the interesting pattern we can find on a calendar.

• Work with a friend and discuss:

a) What pattern can you see in each row? (horizontal)

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b) What pattern can be seen in each column? (vertical)

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c) What patterns do you see in the diagonal from left to right?

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d) What patterns do you see in the diagonal from right to left?

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e) Look at the block marked with a dark line on the calendar. Now determine:

f) The sum of each row: ________________________________________________

g) The sum of each column: _____________________________________________

• What do you notice? _______________________________________________________________

h) The sum of the diagonals: ____________________________________________

• What do you notice? _______________________________________________________________

i) Test now for other "blocks" of numbers on the calendar. What is your conclusion?

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Assessment

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 2.2: We know this when the learner describes, explains and justifies observed relationships or rules in own words.