Tuesday, April 14, 2009

Measuring Up

We have moved our focus in class to measurement for the next several weeks. Students are working on developing their understanding of the concept of length. We begin by using nonstandard measurement to determine the length of items in the classroom. Nonstandard units are units that are the same size, but not typically used to measure length. For example paper clips, linking cubes, toothpicks, Popsicle sticks, etc.

Students are working to understand that the length of something is the measurement of how many units it is. We are also working on proper measurement techniques.

The units cannot overlap. The above image shows an inaccurate measurement because the units used to measure (paperclips) have overlapped in several areas and are not all turned the same way.

The units must fill the entire space. The above image shows an inaccurate measurement because the units used to measure (paperclips) have gaps in between each unit. This is not measuring the full length of the pencil.

The units must go from the starting to the ending point. The above measurement is accurate. It shows that the pencil is 4 paperclips long. It is an accurate measurement because the paperclips are lined up end to end, have no gaps in between, and measure the full length of the pencil.

Next, we move into standard measurement. Here, students use a ruler to measure the length of objects. The ruler must start at the beginning of the object. We will look at measuring with a ruler in two different ways. The first way, students will line up the object to the ruler at the zero mark and measure the length of the object. This is the easiest way for students when they are learning to measure, but it is not the only way to use the ruler to measure.

The second way we will look at the ruler is starting with a piece of the ruler and measuring how long an object is. We will not necessarily be starting with the zero, so students will need to be able to count units measured. The ruler below shows that the pencil is 8 inches long. Students will have to line the pencil up with an inch mark and physically count each inch.

Ruler Practice (game)

More Ruler Practice (Put the game on whole or half setting)

1 comment:

Suzanne said...

As a fifth grade math teacher, I always found that measurement was a struggle for some students. The broken ruler problem in all the FCAT practice books was frustrating because students always figured you just start at O. It is nice to see that even in 2nd grade this will not become a student misconception because your students will have had practice measuring from several different numbers. Measurement is truly a life long skill! Thanks for sharing.