**Standard form** is a way of writing very small and large numbers. The numbers are written in the form ; where “a” is a number between 1 and 10, “m” is an integer (positive or negative) and “n” is base 10.

__Examples: __

- 0.00312 written in
**standard form**= . Very small numbers are represented with negative integers, depending on the number of places move to the*right*in order to get a number between 1 and 10. - 0.912 written in standard form= .Base 10 is raise to the power of negative -1, because only one place is move to the right.
- 980000 written in standard form=. Base 10 is raise to the power of positive 5, because five places are moved to the
*left*in order to obtain a number between 1 and 10 (9.8). - 200.13 written in standard form=. You will see that 2 places are moved to the left in order to obtain a number between 1 and 10 (2.0013) and that base 10 is raise to the power of positive 2. Why? Because only 2 place are move to the left.

Prefixes Used in Science and Technology

**Name of Prefix****Symbol****Numerical Form**Deka

da

10

^{1}Hecto

h

10

^{2}Kilo

K

10

^{3}Mega

M

10

^{6}Giga

G

10

^{9}Tera

T

10

^{12}Peta

P

10

^{15}Exa

E

10

^{18}Zetta

Z

10

^{21}Yotta

Y

10

^{24}Prefixes Use in Science and Technology

**Name of Prefix****Symbol****Numerical Form**Deci

d

10

^{-1}Centi

c

10

^{-2}Milli

m

10

^{-3}Micro

µ

10

^{-6}Nano

n

10

^{-9}Pico

p

10

^{-12}Femto

f

10

^{-15}Atto

a

10

^{-18}Zepto

z

10

^{-21}Yocto

y

10

^{-24}

How to Use Prefixes

Let’s say you worked out a physics question and you got 2million metres for your answer. You can write your answer in standard form or using prefixes. I will also show you the relationship between standard form and prefixes.

2million metres (2,000,000m) written in standard form= or written using prefix= 2Mn. Look at the prefixes table you will see that = Mega (M). So what happen is that is replace by “M” the symbol for Mega (. So in dealing with very small and large numbers you can replace this part of the number “” with the prefix connected to it. I hope that highlight the relationship between standard form and prefixes. Please look at the examples below.

1. 2900= (standard form)= 2.9K (k= kilo= )

2. 0.098m (metre or meter) = = 9.8cm. Please note that “centi” which equal to “” replace the written in standard form with its symbol “c”.

Why is Mass,time and current are called fundamental quantities

Other quantities can be derived from them.