Lesson objective: Students explore length comparisons both directly and indirectly .
This lesson provides an opportunity for students to apply their knowledge and understanding of length comparisons both directly and indirectly. They extend their knowledge to make comparison of a third object. Students will be asked to compare the length of child's shadow in the morning, at midday and in the afternoon. Students will use the words shorter and longer in a sentence to describe the shadow lengths. Students will use the relationship of the morning shadow and afternoon shadow along with the afternoon shadow and midday shadow, to indirectly compare the morning shadow to the midday shadow.
Key Concept students will use:
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Comparing lengths of objects requires taking both endpoints into account.
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If object A is longer than object B and object B is longer than object C, then object A is longer than object C.
Skills students will use:
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two objects with a measurable attribute in common, to see which object has “more of”/”less of” the attribute, and describe the difference.
- compare objects directly and indirectly using a third object
Students engage in Mathematical Practice MP.2 as they reason quantitatively and abstractly.
Students engage in mathematical Practice MP.3 as they construct viable arguments and critique the reasoning of others.
Key vocabulary:
- distance
- direct
- indirect
- length
Special materials needed: