Ruler Fundamentals Second Grade students have very little practice using a ruler to measure. Third grade teachers then have the task of teaching the most basic fundamentals of using a ruler. These prerequisite skills are needed to master the third grade benchmark.
Where do we start? A major error students make while measuring is starting from the edge of the ruler not at the zero. Teachers should begin this unit by addressing this misconception.
Customary vs. Metric Another major error students make while measuring is using either side of the ruler regardless of whether they are being asked to measure in inches or centimeters/millimeters. The Go Math Text book teaches this in isolation. Our recommendation is that this be addressed in the very beginning and have students use the FCAT ruler from day one of the unit. Teachers can repeatedly ask throughout the unit, “which side of the ruler should we be measuring with for this problem?” Teachers should have students identify the two units and compare the two units. Example: Centimeters are smaller than Inches.
Identifying the Whole Unit Before partitioning an inch or centimeter, students need to understand what is a whole unit. Start with identifying the whole numbers. What do these whole numbers mean? When we jump from one whole number to the other we are jumping/measuring one whole unit. One Whole Unit
Identifying the Whole Unit Confirm understanding by not starting at the zero. Jump from one whole unit to the next from somewhere other than zero on the ruler. Finding the measurement of an object not starting on zero is almost always tested on the FCAT 2.0. One Whole Unit