Making a Straw Balance

9th Annual Day of the Teacher Conference

March 26, 2011

CSUEB Concord Campus

Charles Reynes Elementary Science

SpecialistCastro Valley, USD

Making a Straw BalanceMaterials Balance pattern

printed on 110 lb. bond card stock

Mass pieces pattern

Large 8 inch “fat” straw

Hole punch Scissors

Making a Straw Balance Cut out the

parts for the balance.

Punch holes in the handles of the balance pans.

Making a Straw Balance Fold all the

pieces on the dotted lines.

Place the fulcrum on its base.

Making a Straw BalanceUse a ruler to find the center of the straw.Notch the center of the straw with a hole punch.

Making a Straw BalanceCut a slit 4-5 millimeters from each end of the straw.Fold over the slit to attach the balance pan. Once the end is inserted into the holes of the pan, unfold to lock the pan in place.

Slits

Notch

Making a Straw Balance

Place the pans on the base. The notch must rest on the base.

Cut a slit down the middle of a small section of straw. Place this on the balance beam like sleeve. Slide the piece to “zero out” the balance.

Making a Straw Balance Cut out the mass pieces. Cut the centigram pieces into groups of 5 or

10.

Making a Straw Balance Zero out the balance by adjusting the

slider. Place the object to be massed in one pan. Pile mass pieces in the other pan until both

pans are off the table.

Making a Straw Balance Count the pieces to

determine the number of of grams, decigrams, and centigrams. 0 grams 27 decigrams 35 centigrams 7(5 cg)

Making a Straw Balance

Convert to grams. 35 cg: 0.35 grams

27 dg: 2.7 grams

The mass of the penny is 3.05 grams.

Teaching With a Straw Balance

Find the mass of small objects.Compare the mass of pennies minted before and after 1982.

Use the balance to calculate the amount of water in a carrot slice.