Final answer:
While the metric system is the standard in most countries and in scientific contexts, the United States, Great Britain, and parts of Canada do not exclusively use it, with the United States largely maintaining its customary units for everyday use.
Step-by-step explanation:
The statement that all countries use the metric system of measurement is not entirely true. While it is accurate that the metric system, which includes units like meters for length, kilograms for mass, and seconds for time, is widely adopted around the world and is a standard for scientific and mathematical purposes, there are a few exceptions. Specifically, the United States has legally adopted the metric system but continues to use the American system in everyday practice instead of the metric system. Moreover, Great Britain and parts of Canada use a combination of metric and imperial units.
The metric system's structure is designed such that every unit increases by a factor of ten, which is considered much simpler than the non-metric (imperial) systems used elsewhere. It is important to note that the metric system, also known as the International System of Units (SI), is considered the modern form of the metric system and is the most widely used measurement system in the world today.
Maps and references often illustrate that the areas of the world using the metric system (often highlighted in green) include the majority of countries, with notable exceptions such as the United States, indicating that the adoption of the metric system is not ubiquitous.