This week in the garden we learned to measure using rulers. Here are the target standards for the lesson:
- CCSS.Math.Content.K.MD.A.1 Describe measurable attributes of objects, such as length.
- CCSS.Math.Content.K.MD.A.2 Directly compare two objects with a measurable attribute in common, to see which object has “more of”/“less of” the attribute, and describe the difference.
- CCSS.Math.Content.1.MD.A.1 Order three objects by length; compare the lengths of two objects.
- CCSS.Math.Content.1.MD.A.2 Express the length of an object as a whole number of length units, by laying multiple copies of a shorter object (the length unit) end to end; understand that the length measurement of an object is the number of same-size length units that span it with no gaps or overlaps.
- CCSS.Math.Content.2.MD.A.1 Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.
- CCSS.Math.Content.2.MD.A.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.
- CCSS.Math.Content.2.MD.A.3 Estimate lengths using units of inches, feet, centimeters, and meters.
- CCSS.Math.Content.2.MD.A.4 Measure to determine how much longer one object is than another, expressing the length difference in terms of a standard length unit.
Click the link below to see an outline of the lesson:
We first introduced the math tool and modeled how to line up the object at the end of the ruler to find an accurate measurement. We discussed units and how to make accurate estimates of length in inches.
My second and third graders also learned to use a metric ruler and measure in centimeters. We discussed the differences in the units and answered questions such as, “Which is longer – 5 inches or 5 centimeters?” and “If I measured the same object in both units, would we record a greater number for inches or for centimeters?”
When the kids demonstrated mastery of the concepts they were given time to practice independently in the garden – collecting measurements and recording them in their science journals.
As they were working, I pulled small groups to extend their lesson – either ordering okra shortest to longest before measuring to find the range, or comparing objects’ lengths using the terms and symbols for “greater than,” “less than,” or “equal to.” Second and third grade students were also able to tell me how much longer one object was from another by finding the difference between the two.
This lesson will help prepare students for measuring our fall crops as they grow and charting their growth on a line graph.