Question

If you have the following data about a container of pencils,

about how many pencils are estimated to be in the
container?
Mass of Pencils + Container = 2308 grams
Mass of 52 Pencils = 334 grams
Mass of Container ONLY = 437 grams
Approximately, how many pencils are in the container?

Answer 1

Find the mass of the pencils alone by subtracting the mass of the container from the total mass:

Mass of Pencils = Mass of Pencils + Container - Mass of Container

Mass of Pencils = 2308 g - 437 g

Mass of Pencils = 1871 g

Find the mass of one pencil by dividing the mass of 52 pencils by 52:

Mass of 1 Pencil = Mass of 52 Pencils / 52

Mass of 1 Pencil = 334 g / 52

Mass of 1 Pencil = 6.42 g/pencil

Estimate the number of pencils by dividing the mass of the pencils alone by the mass of one pencil:

Number of Pencils = Mass of Pencils / Mass of 1 Pencil

Number of Pencils = 1871 g / 6.42 g/pencil

Number of Pencils ≈ 291