Which base is decimal, base 10, used in everyday counting?

Which base is decimal, base 10, used in everyday counting?

• A. Binary
• B. Octal
• C. Decimal
• D. Hexadecimal

Answer: (C)

Decimal is the base-10 counting system used every day. It relies on ten digits (0 through 9) and place value, so numbers are built from powers of ten—for example, 345 means 3×100 + 4×10 + 5×1. This ten-digit system comes from counting with ten fingers, which is why everyday arithmetic uses base-10. Other bases exist mainly in computing: binary uses two digits (0 and 1), octal uses eight digits (0–7), and hexadecimal uses sixteen digits (0–9 and A–F). So the base used for everyday counting is decimal.

Decimal is the base-10 counting system used every day. It relies on ten digits (0 through 9) and place value, so numbers are built from powers of ten—for example, 345 means 3×100 + 4×10 + 5×1. This ten-digit system comes from counting with ten fingers, which is why everyday arithmetic uses base-10. Other bases exist mainly in computing: binary uses two digits (0 and 1), octal uses eight digits (0–7), and hexadecimal uses sixteen digits (0–9 and A–F). So the base used for everyday counting is decimal.