Prefixes are the preceding factor used to represent very small and very large physical quantities in SI units.

Table below shows the prefixes that you need to know in SPM.

Conversion of prefixes

Prefixes to Normal Number

Example 1:
The frequency of the radio wave is 350M Hz. What is the frequency of the radio wave in Hz?

Mega (M) = 1,000,000 or 106

350MHz = 350 x 106Hz

Example 2:
The thickness of a film is 25nm. What is the thickness in unit meter?

nano (n) = 0.000000001 or 10-9

25nm = 25 x 10-9m

Normal number to Prefixes

Example 3:
0.255 s is equal to how many ms.
mili (m) = 0.001 or 10-3

To write a normal number with prefixes, we divide the number with the value of the prefixes
0.0255 s = 0.0255 ÷ 10-3 = 25.5 ms

Example 4:
Convert 265,500,000 W into GW.
Gega (G) = 1,000,000,000 or 109
265,500,000 W = 265,500,000 ÷ 109 = 0.2655GW

Recommended Videos


Conversion of Number with Perfix to Normal Number

Conversion of Normal Number to Number with Perfix

Conversion of a Prefix to Another Prefix

External Link

The NIST Reference on Prefixes