Index Form

Standard Form

Teacher: Dan Hoang

What is Standard Form?

• Standard Form (sometimes called Standard Index Form) is a way of writing very big and very small numbers using powers of 10

• Example:

   $6.3\times10^{11}$  

How do we use standard form?

• Using standard Form numbers are always written in the form:

   $a\times10^n$  

•  $1\le a\le10$  so there is one non-zero digit before the decimal point

•  $n>0$  for LARGE numbers - how many times  $a$  is multiplied by 10

•  $n<0$  for LARGE numbers - how many times  $a$  is divided by 10

• Do calculations on calculator (if allowed). Otherwise follow rules (including indices) but adjust answer to fit Standard Form (move decimal point and change  $n$ )

Example 1

Example 2

Multiple Choice

Which one is written in standard form?

• $$10.3\times10^{-11}$$

• $$1.03\times10^{-10}$$

That's the end of lesson!

- Thank you -