Why does the metric system matter? How many countries use the Imperial/American system? Do you know any examples of the measurement system before the SI system?

The metric system is highly important as its base is on scientific fact and repeatable standards of measurement. .

Also in the metric system the calculation becomes easy like for eg; if are to represent a billion type number or even bigger than that we can take the use of scientific notation and convert that huge number into the powers of tens this not only makes the process of calculation easy but also saves time.

Metric system has been adopted by almost every country in the world.

There are only three countries that still uses imperial/American system of measurement and those are

Other systems than SI are

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.