Learning Goal
Understand the concept of a ratio
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
Teacher tools for this standard
Lesson Plan · Guided Notes · Exit Ticket · Re-teach · Homework
- Lesson Plan →Objectives, pacing and practice, built from this lesson's brief.
- Guided Notes →One page your students fill in and keep.
- Exit Ticket →Three items at the end of class. No student accounts.
- Re-teach →After an exit ticket: who missed what, and what to do tomorrow.
- Homework →Assign practice; it grades itself.
Understand the concept of a ratio and use ratio language to describe a ratio relationship between two quantities. For example, "The ratio of wings to beaks in the bird house at the zoo was 2:1, because for every 2 wings there was 1 beak." "For every vote candidate A received, candidate C received nearly three votes."
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Understand the concept of a ratio and use ratio language to describe a ratio relationship between two quantities. For example, "The ratio of wings to beaks in the bird house at the zoo was 2:1, because for every 2 wings there was 1 beak." "For every vote candidate A received, candidate C received nearly three votes."
What you'll learn
- Distinguish between an *additive* comparison ("4 more apples than oranges") and a *multiplicative* comparison ("3 apples for every 1 orange"), and identify the ratio as the multiplicative comparison.
- Use **ratio language** -- *"for every ___ there are ___"* and *"the ratio of ___ to ___ is ___ to ___"* -- to describe a ratio relationship between two quantities.
- Write a ratio in all three standard notations: *a* to *b*, *a:b*, and *a/b*, and translate among them.
- Recognize that the order of a ratio matters -- *a:b* and *b:a* describe different relationships.
- Classify a ratio as **part-to-part** (comparing two parts of a group) or **part-to-whole** (comparing a part to the total), and determine the whole when the ratio is part-to-whole.
- Read a part-to-whole ratio as a fraction of the whole (boys are 2/5 of the class) while recognizing that this fraction-of-the-whole reading does not apply to part-to-part ratios.
- Write a complete ratio statement for a real-world situation, including units, order, all three notations, ratio language, and part-to-part / part-to-whole classification.
Slides
Step through the lesson, or watch it as a narrated video
Ratio concept and language
✓ Start herePractice
Try it on your own
Animated Videos
Short animated explanations of the key idea • 4 animated videos