Figured bass indicates the intervals above the bass that should be played for each sonority.
Sometimes these intervals are literal intervals, but often they do not indicate the octave of each note or the ordering of the voices.
For example, if the figures are 8/5/3 the player could realize this in octave, third, or fifth spacing. Most times, composers would indicate just 5/3 or 5 or 3 or no figures for an 8/5/3 chord in any spacing.
When you see no figures you may play or write a 3, 5, or 8 above the bass. The following shows which intervals one should play based on the number of voices available:
|2-voice figuring||3-voice figuring||4-voice figuring|
|3||5/3 or 8/3||8/5/3|
Practice these in all major and minor keys using Keyboard Buddy (unit 1-1)