Maths revision

Reciprocals:

When it comes to doing reciprocals the easiest thing to do is just flip the fraction round: 

a) 8/5  = 5/8                                b) 6/2 = 2/6

When it comes to whole numbers no fractions just a plain number put a 1 ontop of it:

a) 8 = 1/8                                    b) 9 = 1/9

When you have mixed numbers you have to turn the mixed fraction into a improper fraction:

a) 3 1/2 =  3 x 2 + 1 = 7 = 7/2  =  2/7 is the reciprocal.

Standard from P1:

Standard form makes numbers easier to understand and read. The number has to be between 1 - 10 for it to work. If you are working with decimal numbers the power above the ten has to be -ve whereas if the number is a whole number then the power above the 10 is +ve.

a) 215,000,000: 2.15 x 10 8 

b) 234,500: 2.345 x 10 5 

C) 0.00054: 5.4 x 10 -4

d) 0.1234: 1.234 x 10 -1

Standard form P2:

Sometimes you might get standard form questions like:

a) (1.2 x 10 2) x (3 x 10 3)   1.2 x 3 = 3.6   2 + 3 = 5 = 3.6 x 10 5

b) 8 x 10 5

   2 x 10 3   = 8/2 = 4   5 - 3 = 2             = 4 x 10 2 

c) 5.1 x 10 8 + 1.45 x 10 8  = 6.55 x 10 8

5.1 + 1.45 = 6.55    

d) 9.6 x 10 -7 - 6.3 x 10 -7  = 3.3 x 10 -7

Squares and cubes:

Sometimes you might get a factions such as:

(3/4)squared = 3squared and 4squared... = 9/16

Or

(3/5)cubed = 3cubed and 5cubed... = 27/125

Formula:

Cubed = b x b x b

Squared = b x b 

Fractional powers and roots:

Squares, cubes, square roots and cube roots can be written in a difficult way. In way you might not undrstand:

a) 8 2/3 this means cube root and square the answer. The denominator is the root and the numerator is the square or cube. = 8 cube rooted is 2 and square is 4.

b) 9/100 3/2 = 100 square rooted = 10   9 square rooted = 3 and cube it all... 27/100

c) 49 -1/2 = 1/49 qhen you have a - fraction you have to make it a reciprocal and add a one or flip the fraction round. So 1/49 = square root = 1/7 which is 7

d) 64/125 -1/3 = 125/64 1/3 = cube root it = 5/4

DTS triangle:

There is a triangle which is D = Distance S = Speed T = Time

in the triangle it is D…