Standard form is used to represent either very large or very small numbers. Calculators normally have a function to use standard form. However, you must understand how it works on your calculator to use it.
Standard form is given in the form: a × 10N where a is a number 1 up to, but not including 10, and N is any integer. Exam papers will normally include a question which includes standard form. It is important that these are answered correctly as above.
Examples:
40 = 4 × 101 = 4 × 10
500 = 5 × 102
0.0005 = 5 × 10-4
1553.158 = 1.553158 × 103