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Whole class activity:
number machines with 1 & 2 steps on OHP or board
OR
Find the missing number in equations such as:
5 + ? = 8 |
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| - Use
letter symbols to represent unknown numbers or variables;
know meaning of the woeds term, expression, equation |
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algebra
equals
equation
expression
solve
solution
symbol
value
unknown
true, false
inverse
variable
order of operations |
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| 'a + b = 12' -
find all a, b pairs for positive integers;extend
to negative numbers & non-integers |
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Activity
suggestions:
1) Written activity using symbols, then letters,
to represent unknown numbers, eg: 5 + ? = 8 ........
5 + x = 8
Include;
- expressions & equations
- finite solutions, eg: for 3 + n = 5
- & infinite solutions, eg: for y = 3x
eg: Find
the Missing Numbers (Part 1 uses boxes; Part
2 uses letters)
2) Review language of algebra, eg:2 x 4 = 4 + 4
? 2 x a = a + a; etc 5 x 5 = 5² ? a x a = a²
3) Written activity , using letter symbols to write
down an word expression or equation; & vv |
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How many solutions
for
y = 2x?
x + y = 16?
Is there a solution that fits both? |
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'I'm thinking of
a no & when I double it, I get 7...'
- Number (or Function) machine?
- Equation?
- Solution?
Converse: Give equation, what is the word puzzle?
Extend to 2-step equations. |
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Use 'True or False'
questions to highlight difference between:
2n & n + 2
n² & 2n
2n² & (2n²)
3c + 5 & 3(c + 5) |
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Review BODMAS for
numbers with Qs such as:'Place brackets, if necessary,
to make these correct,
20 - 2 x 8-3 = 1
20 - 2 x 8-3 = 10
20 - 2 x 8-3 = 141
20 - 2 x 8-3 = 7
OR egs: on p 86 |
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| - Understand
that algebraic expressions follow the same conventions
order as arithmetic operations |
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Extend Starter to
symbols, eg: using ' which is bigger - a+ b or b
+ a? a + a or 2 a?
Repeat activity 'I'm thinking of a no & when
I double it, I get 7 ...', but find solution using
inverse operations, eg:
X x 2 + 1 = 4
÷ 2 - 1 |
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1) Develop Introductory
Ideas through range of activities
2) Extend use of BODMAS from numbers to symbols
(see pp 84 - 85 & p 114), (using commutative
& associative laws) |
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Provided an extended
chain problem, eg; with 6 steps;
a) solve it!
b) write it!
c) Number machine & inverses?
Eg: I'm thinking of a number, I double it add 4,
halve it, divide by 6 & subtract 1. I get 1.
Starting No? |
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