One

How to type it

Left pinky. Introduced in Lesson 20: Numbers: 1 to 5.

Common uses

• One is the first counting number and marks first place.
• The United States, Canada, and much of the Caribbean share the international calling code 1.

Less common uses

• In computing, 1 often stands for on and 0 for off.
• One is neither prime nor composite.
• Multiplying any number by 1 leaves it unchanged.