I’ve already written about using a classroom balance that encourages children to weigh objects “relatively” to a standard weight or “relatively” to another object.  Through trial and error, they can see if an object is lighter or heavier than another object and then adjust the balance until they make it the same.

In supermarkets, there are large scales for weighing fruits and vegetables.  When items are placed in the basket underneath, the dial moves and the weight can be read. They also have scales that weigh items on top.  These can be digital or analog.

Bathroom scales weigh people as do scales at the doctor’s office.  These can look very different but they do exactly the same job.

I think it would be really interesting to have several scales available simultaneously for children to explore.  I know that most of us don’t have access to some of these machines, but keep your eyes open at garage sales, on Craig’s list, or in the newspaper.  We have an antique doctor’s scale on our back deck that we inherited from a friend.  Not only is it beautiful, but it still works.

Learning Standard B – Begin to make estimates of measurements.

Benchmarks

7.B.ECa  Practice estimating in everyday play and solving everyday measurement problems.

Example Performance Descriptors

Make predictions and estimations during play (e.g., estimate how many scoops of sand it will take to fill a small bucket at the sand table).

Estimate to solve a task (e.g., during block play, estimate how many blocks are needed to make the road being constructed reach the wall).

WOW!  I wish this one had performance descriptors that indicated development over time.  Knowing that it will take 3 buckets of sand to fill a large container requires a certain amount of conservation.  A child needs to know that when put together, the 3 buckets are about the same as the large container.  If Piaget was even close to being right about a young child’s ability to conserve quantity, then this task is not very developmentally appropriate.

Now if the descriptor said, “Estimate if it will take many buckets to fill the sand table, or only a few buckets to fill the sand table” we might see children more able to “estimate” the quantity (if indeed estimation of measurement is the expectation).

What do you think?  Can your kids tell you about how many blocks they will need to construct a road across the rug?

Learning Standard C – Explore tools used for measurement

Benchmarks

7.C.ECa  Explore the use of standard instruments to measure objects and quantities with teacher assistance.

Example Performance Indicators

Use standards measuring tools, with teacher assistance (e.g., use a measuring tape to measure how far a child can jump).

Use a variety of similar tools for measurement (e.g., use both balance scales and scales that provide a numerical weight to explore objects in the classroom).

Know that thermometers measure temperature and clocks measure time.

I like this one better than the last.  As least it leaves room for developmental variability and allows for adult assistance.  A tape measure is a great classroom tool, that is pretty interesting in and of itself (just pulling it out and then releasing it) so as a tool is is engaging. Measuring with it and understanding what that means is a bit more complicated. However,  within the construct of play, I can see children using the tape measure in the was it is meant to be used.

Balance scales and other kinds of scales are also really wonderful measurement tools for the classroom. Trying to get a balance scale to “balance” is a fun task for children and and “weighing” things (especially themselves if you have a bathroom scale in the classroom)is also developmentally appropriate.

They make all of these things so they are easy-to-use with large numbers and clear indicators for young children.  Making these tools available throughout the day, during play, will allow children to get comfortable with them  and will give them opportunities to explore their functions.