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9.02 Measure and estimate mass

Lesson

Are you ready?

Do you remember the units of mass? Let's try these problems to practice.

It is most appropriate to use grams to measure:

  1. Your mass

    A

    Your pencil case

    B

    A bus

    C

It is most appropriate to use kilograms to measure:

  1. An eraser

    A

    A button

    B

    A bike

    C

Learn

When measuring the mass of an object, we have two main methods.

  1. We can balance a scale with weights that we already know. 
  2. We can measure the mass by reading a mechanical scale.

This video looks at measuring the mass of objects using a scale. 

It is useful to know the mass of some common objects so that we can estimate the mass of new objects.

Apply

Question 1

The scale below shows an object balanced evenly with a particular set of weights.

  1. The following weights were on the scale:

    What is the total mass of the object?

Question 2

What measurement is indicated on this scale?

QUESTION 3

Choose the best estimate for the mass of a school student.

  1. $40$40 g

    A

    $400$400 g

    B

    $4$4 kg

    C

    $40$40 kg

    D

Remember!

A gram has a mass similar to a piece of paper, or a feather. A kilogram has a mass similar to a $1$1 liter bottle of milk or juice. We can measure the mass of objects with different types of scales. Mechanical scales are just like a number line, but in a circle.

Outcomes

3.MD.A.2

Measure and estimate liquid volumes and masses of objects using metric units. (Excludes compound units such as cm3 and finding the geometric volume of a container.) Add, subtract, multiply, or divide to solve one-step word problems involving masses or volumes that are given in the same units. Excludes multiplicative comparison problems (problems involving notions of “times as much”).

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