# In this lesson, students check their “which one is heavier” estimates by using a pan balance

Subject:

Math

K, 1

Title – Introducing the concept of mass
Primary Subject – Math
Grade Level – K – 1

Objective: Children will compare objects and attempt to rank them according to estimations of their comparative mass. They will check their estimates by using a set of pan balances.

Materials: variety of objects… e.g. children’s toys, books, construction materials, shoes, small containers of food, play dough, clay and sets of pan balances.

Step 1: Teacher displays a variety of objects. Children are to guess which is the heaviest, lightest, whether any would be the same weight. Children are given the opportunity to hold the objects to assist with their estimations.

Step 2: Teacher questions children on possible methods of discovering how accurate their guesses are and introduces pan balances.

Step 3: Children are given the chance to work in small groups (2-4 per group) to experiment with the objects and pan balances to determine a method of finding the heavier of two objects.

Step 4: Findings are shared in a whole group situation with emphasis on explaining that the heavier of two objects will always pull that side of the balance scales lower.

Step 5: Children will move back into original groups and each child will be given a lump of play dough or clay and asked to make two or three objects…e.g. animals. They then attempt to rank all the objects made by their group according to their estimated mass.

Step 6: Children use pan balances to check their estimations.

Conclusion: Whole group re-forms to share findings. A similar activity could then be set up as a learning centre as further reinforcement of this concept.