Objective

By the end of this lesson, you will be able to estimate, measure, and compare the masses of objects using kilograms and grams.

Materials and Prep

Materials: Several objects of different masses, a scale that measures in kilograms and grams.

Prep: Make sure the scale is set to zero before starting the activities.

Activities

• Estimation Game: Guess the mass of each object before weighing it. See how close your estimates are to the actual measurements.

• Weighing Objects: Use the scale to measure the mass of each object in kilograms and grams. Record your measurements.

• Comparing Masses: Arrange the objects from lightest to heaviest based on the measurements. Can you explain why some objects are heavier than others?

Talking Points

• What is mass?
  "Mass is how much stuff is in an object. It tells us how heavy or light something is."

• What is a kilogram?
  "A kilogram is a unit of measurement for mass. It is used for heavier objects."

• What is a gram?
  "A gram is a smaller unit of measurement for mass. It is used for lighter objects."

• Why do we estimate first?
  "Estimating helps us make a guess before we measure. It's like making a prediction."

• How do we compare masses?
  "We compare masses by looking at the numbers on the scale. The bigger number means the object is heavier."