Ohaus PRIMER BALANCE User Manual
PRIMER BALANCE
ACTIVITY GUIDE
Primer Balance
Accurate, simple to use, easy to clean and student proof.
Your students' first introduction to the principles of balancing
are best demonstrated with this new design primer balance.
2000 g capacity, 1 g sensitivity.
PRIMER® BALANCE
ACTIVITY GUIDE
INTRODUCTION
Children develop measurement concepts through interactions with objects
in their environment. They gain these concepts by climbing trees, lifting
toys, touching hot and cold surfaces, and doing a multitude of things called
"everyday life". The teacher’s role is to help the student integrate what he
or she knows about the world with the formal lessons taught in the
classroom.
An important part in helping students to integrate and expand their knowledge of measurement is to present lessons in a concrete form. A
suggested teaching sequence for accomplishing this goal is shown below:
SEQUENCING ACTIVITIES FOR MEASURING MASS
The chart above implies that students of any age should have experiences
comparing the relative mass of objects using direct comparison techni ques
(using all five senses). If students are unable to decide which of two
materials has the greater mass, they may elect to use a balance to resolve
the problem.
Initial work with the balance can be carried out successfully using
nonstandard units of measure. The student can use almost any available
object as his unit for comparison. Later, for convenience and accuracy,
comparisons can be made using standard units.
2
USING THE PRIMER® BALANCE
The Primer Balance is rugged and can be used by students with the
knowledge that it will not be damaged through normal use. The balance
may be taken apart to see how it is constructed. Each of the balance pans
may be loaded with all types of materials: sand, water, books, rocks, etc.
Since there is very little that will damage the Primer Balance, students may
be given freedom to explore how it works.
After they have had an opportunity to explore the working of the balance on
their own, the activities in this guide may be duplicated and introduced.
Buckets hold liter box for
Sliding weight for zero
adjustment
Buckets graduated to 500 ml
easily lifted on and off
use as pan balance
Balances with heavy masses
up to 2 kg, yet sensitive to 1 g.
3
Accurate even when objects are
placed on the edge of buckets
does it balance?
OBJECTIVE:
MATERIALS:
PROCEDURE:
Objects Heaviest Lightest
To make accurate comparisons of the mass of two
similar objects.
Primer Balance
Pairs of objects that have similiar but unequal
mass.
For example:
2 rubber erasers (used)
2 oranges
2 crayons (used)
1. Check the reading on the front of the balance to
see if it is in alignment. If it is out of balance,
have your teacher show you how to adjust it.
2. Use a marking pen to mark each pair of
objects. (Mark one object "A" and the other
"B".) Weigh each pair of objects. List them and
record the results by placing an "A" or "B" in the
proper column in the following chart.
2 pebbles
2 pencils (used)
2 potatoes
4
fruits and vegetables
OBJECTIVE:
MATERIALS:
PROCEDURE:
To use a balance to order objects by mass.
Primer Balance
One each:
Banana
Apple
Grapefruit
1. Look at the fruits and vegetables: list them in
order from the lightest to the heaviest.
Record your guess in the following chart.
2. Compare the weight of the fruits and
vegetables to see if your guess is correct.
Order
by
Guessing
Potato
Lemon
Carrot
Order
by
Weighing
Lightest
Lightest
Heaviest
Heaviest
5
Nonstandard
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