Moving, going, or growing upward: an
1 a : rising or increasing to higher levels, values, or degrees <
Arranged from smallest to largest. Increasing. Example: 3, 9, 12, 55 are in
to go up : to rise or move toward the sky. : to slope or lead upward. : to rise to a higher or more powerful position in a government, company, etc. Source: ...
Numbers are said to be in
go up or climb, rise or move up through the air Meaning, pronunciation, example sentences, and more from Oxford Dictionaries.