Mathematics, Measurement (includes Time)

Grade 1- 3

Objective

In this activity, children will use tables showing the ratios between ounces and pounds, grams and kilograms, and pounds and kilograms. They estimate whether an object should be weighed in ounces or pounds and whether an object should be weighed in grams or kilograms. The children use calculators to convert pounds to kilograms and kilograms to pounds.

Directions

1. Introduce the concept of weight through modeling how to use the bathroom scale and the balance. Ask the children which kind of scale is best for weighing heavy objects (bathroom scale) and which kind of scale is best for weighing light objects (balance).
2. Have the children practice weighing different objects with the balance. Then order the objects by weight, from lightest to heaviest.
   

• Step 1: Place the item to be weighed (crayons) on one side of the balance.
  
• Step 2: Put the weights (teddy bear counters) one at a time on the other side of the balance. Continue adding weights to the balance until both sides of the balance are at the same level.
• Step 3: Add up the weights used to make the crayons balance.
  
• Step 4: Record the weight of the crayons. Distribute the activity sheets to students.

Resources

• calculators
• bathroom scale
• balances with weights (or use teddy bear counters, beans, unifix or multilink cubes, etc.)
• items to weigh-fruit, crayons, paper towels, erasers, books, etc.