Final answer:
The prefix that multiplies the base unit by 1,000,000 is Mega (M), such as in 1 Megameter (Mm) equating to 1,000,000 meters and a Megabyte (MB) for one million bytes in computer memory.
Step-by-step explanation:
The prefix that multiplies the base unit by 1,000,000 is Mega (M). For example, 1 Megameter (Mm) is equivalent to 1,000,000 meters (10¶ m). In the context of computer memory, the unit for one million bytes is a Megabyte (MB).
It is important to note that each SI prefix represents a power of 10, and in cases where a letter appears twice in any list of prefixes, capitalization matters: uppercase denotes exponents larger than one and lowercase for exponents less than one, as indicated with M for Mega (10¶) and m for milli (10⁻³).