Alicia and jeremy weigh a cell phone on a digital scale. they write down 113 but forget to record the unit. which unit of measurement is correct? how do you know?

For this case, what you should keep in mind is that the unit that must be written next to the number is a unit of mass.

The unit of mass in the international system is kilograms or equivalently:

m: [Kg]

We know that physically it is impossible for a phone to weigh 113 kilograms.

Therefore, a unit of equivalent mass must be written.

An ideal weight, would be for example:

113 grams

Note: the conversion between kilograms and grams is:

1 kilogram = 1000 grams

A unit of measurement that is correct can be:

113 grams