Scientific Notation

when writing in scientific notation, the first number is under 10 and for x10^k,

k= integer

Example 500000

Order of operations:

Place the parentheses () in the following calculation to make it a corret statement:

10-5x9+3 =60

Answer

(10-5) x (9+3) =60

Directed numbers:

When using relative position on a numberline, objects might be to the right or the left of the position, to denote the direction, one can use + and -

Calculate

Example: a. (-3-3) : (1-7)

                   b. 6 - [15- (-3-2)]

Answer: a. (-3-3) : (1-7)

            = -6 : (-6)

= 1

b. 6- [ 15 - (-3-2)

= 6 - [15-5]

= 6-20 = -14

Question

a. 2⁄5 + 3⁄7

b. What is the perimeter and earea of a rectangle with length of 12.2 cm and width of 7.5cm?

c. A chemical is stored at -34.8⁰C. It is heated so that the temperature rises by 81.9⁰C. What is its new temperature

Answer

a. 2⁄5 + 3⁄7 = 14⁄30 = 15⁄30 = 20⁄30= 2⁄3

b. Perimeter = 39.4

c. 81.9 - 34.8 = 47.1⁰C

Converting

Decimal - % = multiply by 100

Decimal - Fraction = Count the amount of zeros and put the amount on the top

Fraction - % = Converting the fraction to a decimal and multiply by 100

Fraction - Decimal = divide the numerator by the denominator

Percentage - Decimal = Divide the percentage by 100

Percentage - fraction = the percentage over 100

FRACTION - DECIMAL - PERCENTAGE

1/5               0.2                 20%

1/50             0.02                2%

1/20             0.05                5%