Zusammenfassung der Ressource
Yr 8 Maths (1st Semester)
- Pythagoras' Theorum
- E.g. For hypotenuse (longest side/c) a^2 + b^2 = c^2 see below.
- Algebraic Techniques
- Simplifying Equations
- Adding and Subtracting like terms
- E.g. 7x + 7y + 3x + 3y = ?, 7x
+ 3x = 10x, 7y + 3y = 10y
therfore, ? = 10x + 10y.
- Multiplying and Dividing like terms
- E.g. 3x / x = ?, x / x = 1, 3 *
1 = 3 therefore, ? = 3.
- Expanding Equations
- E.g. 3(x + 4) = ?, 3 * x = 3x,
3 * 4 = 12 therefore, ? = 3x
+ 12.
- Percentages and Financial Maths
- What Percentage of a Shape is Shaded
- E.g. For example to the right 14 out
of 25 blocks are shaded or 14/25.
Make it over 100, i.e. multiply by
4/4 so it's 56/100 or 56%.
- Converting between;
Decimals, Fractions and
Percentages
- E.g. For 8.3% as a decimal. 8.3 / 100 is
0.083, so 8.3% is 0.083. Or you could
move the decimal point two places to
the left and remove the percent sign.
- E.g. For 15/2 as a percentage. 15 / 2 is
7.5. 7.5 x 100 is 750, so 15/2 is 750%
- Finding percentage of whole numbers
- E.g. For 30% of 140L, First find 1%
of 140L, 140 / 100 =
1.4, then find the 1.4 * 30 = 30% of 140L = 42L
- Taking away/Adding G.S.T.
- E.g. Finding the cost of a chair without G.S.T.
which cost $33. G.S.T. is 10%, so $33
represents 110%. $33 / 110 * 10 = $3, so $3
represents 10%, $3 x 10 = $30, so therefore
the cost of the chair without G.S.T. is $30
- Rational vs Irrational Numbers
- An irrational number is a number that cannot be written.
- E.g. Pi, square root(2), e
- A rational number is a number that
can be written down in it's actual
form or just repeats itself.
- E.g. 1, 1.0, 1.32, 1.525252..., 3/6, 175.5%
- Linear Relationships
- Basic names of the parts of a number plane
- How to work out rule from a table of values (and vice versa)
- y goes up by 3 each time, so the RSF (Rule so far) is y =
3x. If we use the x = 1 as an example 3 * 1 is 3, but y is
-1, so you have to take away 4, so the rule is 3x - 4
- How to put a table of values on a number plane. If x = 2, go along the x axis until you get to 2 then go up y.