Transcript 01 General Number Patterns

General Mathematics
Preliminary
General Number
Patterns
Stage 6 - Year 11
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1
General Number Pattern 1/5
A number pattern is a series of numbers
that obeys a rule.
Questions to ask.
Add
•Does the pattern increase (or decrease)
by a given amount?
Subtract
•Does the pattern increase (or decrease)
by a given factor?
Multiply
Divide
2
General Number Patterns 2/5
7, 11, 15, 19, . . .
Does the pattern increase (or decrease)
by a given amount?
3
General Number Patterns 2/5
...
7, 11, 15, 19, 23,27.
By how much?
11 – 7 = +4
15 – 11 = +4
19 – 15 = +4
Rule
Start at 7:
add 4
The next two numbers are …
4
General Number Patterns 3/5
27,25, 23, 21, . . .
Does the pattern increase (or decrease)
by a given amount?
Yes
Yes
Yes
Yes
5
General Number Patterns 3/5
. . .17.
27,25, 23, 21, 19,
By how much?
25 – 27 = -2
23 – 25 = -2
21 – 23 = -2
Rule
Start at 27:
minus 2
The next two numbers are …
6
General Number Patterns 4/5
3, 6, 12, 24, . . .
Does the pattern increase (or decrease)
by a given amount?
No!
7
General Number Patterns 4/5
3, 6, 12, 24, . . .
Does the pattern increase (or decrease)
by a given factor?
Yes
8
General Number Patterns 4/5
3, 6, 12, 24, 48,
. . .96.
By what factor?
6 ÷ 3 = 2
12 ÷ 6 = 2
24 ÷ 12 = 2
Rule
Start at 3:
times 2
The next two numbers are …
9
General Number Patterns 5/5
32, 16, 8, 4,
...
Does the pattern increase (or decrease)
by a given amount?
10
General Number Patterns 5/5
32, 16, 8, 4, . . .
Does the pattern increase (or decrease)
by a given factor?
11
General Number Patterns 5/5
.
. .1.
32, 16, 8, 4, 2,
By what factor?
16 ÷ 32 = 0.5
Rule
8 ÷ 16 = 0.5 Start at 32:
divide by 2
4 ÷ 8 = 0.5
x0.5
1
( /
2)
is the same as ÷2
The next two numbers are …
12