9th Grade Math Lesson
Placing Real Numbers: Rational, Irrational, and Everything In Between
Shared by A STEM Educator
9th GradeBTC Style / Thinking Classrooms50 min
Learning Objective
Students will compare and order rational and irrational numbers by converting to decimal approximations and reasoning about their placement on a number line.
Lesson Overview
Students progress from comparing familiar decimals and fractions to ordering irrational numbers by locating them on a number line, culminating in multi-step comparison tasks mixing rational and irrational values.
Materials
- Whiteboard and markers (vertical surface preferred)
- Pencil and paper
- Basic calculator (phone calculator is fine)
Scaffolded Task Progression
1Task 1
Place these numbers in order from least to greatest on a number line. Mark each one with a dot and its label.
0.4, \1/3, \ 0.6, \2/3
Then write: which two numbers are closest together?
0.4, \1/3, \ 0.6, \2/3
Then write: which two numbers are closest together?
2Task 2
Now add to your number line from Task 1.
Without a calculator, decide: is closer to or closer to ? Explain your reasoning to your group.
Then use a calculator to check: what decimal does equal?
Without a calculator, decide: is closer to or closer to ? Explain your reasoning to your group.
Then use a calculator to check: what decimal does equal?
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