Fourth graders discover that an angle is an amount of turn measured in degrees, learn to read a protractor, and connect right, acute, and obtuse angles to the numbers that describe them.
Students will be able to…
Two angles both look like corners, but one is barely open and one is nearly flat. How do you measure exactly how open an angle is, so you can compare them with a number?
Project this and open each card to explore degrees, the protractor, and how to measure an angle.
Tap any phase to open the teacher moves and student actions.
Two angles both look like corners, but one is barely open and one is nearly flat. How do you measure exactly how open an angle is, so you can compare them with a number?
Students explore how angles are measured.
Students read angle measures.
Students draw measured angles.
Students reflect on measuring angles.
Aligned to the Common Core State Standards for Mathematics.
Understand that an angle is measured in degrees as a fraction of a full turn.
Measure and draw angles in whole-number degrees using a protractor.
Recognize that an angle can be split into parts that add up.
Use appropriate tools strategically.
Preview the three formative checks. Tap “Sample answer” to see what mastery looks like — hide them before you print for students.
Have students draw a right, acute, and obtuse angle, measure each with a protractor, and label the degrees, so measuring becomes real practice. A printable measuring-angles worksheet is in the Mathematics library.
Tap a card to flip it, then rate whether you knew it. Built from this lesson’s vocabulary.
A quick self-check with instant feedback, drawn from this lesson’s key terms.
A print-and-go review sheet with a built-in answer key. Tap “Show answer key” to reveal answers, or print the clean version for students.