Monday, October 3, 2011

Meter Stick: What do All Those Lines Mean?

Ever wonder if your students even understand a metric stick or not? Don’t just teach your students how to use a meter stick…create a meter ruler together and help them really understand the base 10 system behind it.

(I wish I could show you the students expressions on their faces...they were so involved in the activity!)

1.      Discussion
First, make a connection between what students already know (the yardstick) and the meter ruler.  Do this by presenting a concrete model of both measuring tools- the yardstick and the meter stick. Your students should notice that the meter ruler is longer in length than the yardstick.  One meter is about 39.37 inches or “About 39 ½ inches.” Cut out a model of a large rectangle 100 inches long. I use vinyl felt-backed tablecloth material from Hancock Fabric, but roll paper could be used too.

2.      Discuss the fact that the metric ruler is based on multiples of ten. As a whole group, count orally by tens to 100. The meter will be divided into ten “decimeters” (tenths of a meter) and can be seen on the meter ruler as 10, 20, 30,40,50,60,70,80,90 and 100 centimeters. Cut out 10 equal sections 10 inches long that will represent the decimeters from "foam sheets". Determine a point a short length in from the end of the vinyl ruler and label it “0”. Lay the foam sections on the large vinyl ruler.  Please take time discussing the fact that each standard unit is the same size.  You can make 2 smaller sections ( 5" and 7" )and use them initially to show the students that varying sized units cannot be used. Hopefully one student will notice that the segments are not all the same length.) Write the word decimeter on the first foam decimeter section.

3.      Each of those sections will be divided into ten equal size “centimeters” (Hundredths of a meter). The centimeters will be counted from 1 to 100. Use 1 inch color tiles and have your students lay them on the edge of the vinyl ruler to represent the 100 centimeters. On the first provided section, actually draw the centimeters tic marks on the foam decimeter section. Label the numbers 10, 20, 30, 40…100 on the appropriate one inch tiles.
4.      Next, divide each centimeter into 10 millimeters.  Discuss the connection that there are 1000 millimeters in one meter or 100 centimeters times 10= 1000.

Have a student select a point on the ruler and determine the measurement. For example, 43 millimeters is found by counting the centimeters...4 which stands for 40 millimeters and then counting the millimeters beyond the 4 centimeters…3 more millimeters.

5.      Summarize the presentation by asking several children to state one idea about the meter ruler that was discussed today.
6.      Application:  Now let the students practice the skill by measuring objects or drawing lines of certain length either individually or with a partner.
Common Core Standard Connection
Measure and estimate lengths in standard units.
2.MD.1. Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.
2.MD.2. Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.
2.MD.3. Estimate lengths using units of inches, feet, centimeters, and meters.
2.MD.4. Measure to determine how much longer one object is than another, expressing the length difference in terms of a standard length unit.

4.MD.1. Know relative sizes of measurement units within one system of units including km, m, cm; kg, g; lb, oz.; l, ml; hr, min, sec. Within a single system of measurement, express measurements in a larger unit in terms of a smaller unit. Record measurement equivalents in a two-column table. For example, know that 1 ft is 12 times as long as 1 in. Express the length of a 4 ft snake as 48 in. Generate a conversion table for feet and inches listing the number pairs (1, 12), (2, 24), (3, 36), ...
Deborah

1 comment :

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