Maths

- Prime number is divisible by:

itself and 1

- 1 is not a prime number:

here are some prime numbers: 7, 11 and 23

Mixed number to improper fraction:

1)   3 4/5 = 3+4/5                                      2) 4 6/7 = 4+6/7

               =15/5 + 4/5                                             =28/7 + 6/7

               =19/5                                                      =34/7

Improper fraction to mixed number:

1)   29/8 = 3 5/8                                        2) 26/6 = 4 2/6

                                                                             = 4 1/3

Addding fractions:

1) 3/11 + 7/11 = 10/11                         2) 9/20 + 3/10 = 9/20+ 6/20 

   = 15/20

   = 3/4

Subtracting fractions:

1) 7/9 - 5/9 = 2/9                                 2) 3/4 - 1/2 = 1/4

Multiplying fractions:

1) 1/3 of 2/5 = 1/3 * 2/5                                   2) 7 1/2 * 4/5

                    = 2/15                                                15/2 * 4/5 = 6/1

                    = 6

Dividing fractions:

1) 5/6 ÷ 11/30 = 5/6 * 30/11                              2) 4 ÷ 1/3 = 12             

                      = 25/11

                      = 2 3/11

REMEMBER :

AREA OF A TRIANGLE = 1/2 ( b*h)          

Composite shape:

- a composite shape is made up of 2 or more shapes.

- should b edivided into rectangles or triangles.

- then both of the areas should be added together.

- useful to think of temperature when dealing with negative numbers.

- when 2 signs are placed together they should be replaced by one sign.

++ = +            if signs are the same replace with "+"

- - = +

+ - = -             if signs are different replace with "-"

- + = -

REMEMBER:

- ANGLES on a STRAIGHT LINE ADD UP TO 180*

- ANGLES on a POINT ADD UP TO 360*

- ANGLES in a TRIANGLE ADD UP TO 180*

- ANGLES in a QUADRILATERAL 360*

- VERTICALLY OPPOSITE ANGLES ARE EQUAL