Similar to −1

400 (number)#470s

476 (number)

477 (number)

478 (number)

479 (number)#479s

400 (number)#480s

484 (number)

486 (number)

+1

1 + 1 + 1 + 1 + ⋯

1/2 + 1/4 + 1/8 + 1/16 + ⋯

One-form (differential geometry)

Root of unity

Uniqueness quantification

One-dimensional space

Unary numeral system

Unipedalism

Empty product

Hapax legomenon

Unit circle

Unit disk

Unit sphere

Unit interval

Unit square

Unit fraction

Unit vector

Singleton (mathematics)