In Texas, measuring angles is a new objective for fourth graders. Therefore it’s so important, and so much fun, to introduce them with manipulatives. We start off by using our arms. Students will touch one fist to the other elbow (the vertex) and adjust their arms to form a ninety degree (right) angle. Then we can open the angle to create obtuse and close it to create acute.
We also use other classroom supplies to form right, acute, and obtuse angles.
Then we point out angles everywhere: floor and ceiling tiles in the classroom, tables in the cafeteria, the hands on the clock, and even lines and shadows on the playground. I also make sure that students always have access to a blank index card. They can place any of the right corners into an angle to determine whether the angle is a right angle, or smaller than a right angle (acute), or larger than a right angle (obtuse).
Next it’s time to measure! It takes some practice to make sure that the midpoint of the protractor is placed exactly on the vertex of the angle, and that one arm is lined up evenly. And because a protractor is labeled in both directions, we review the meanings of acute and obtuse. Then make sure to use the smaller numbers for an acute angle and the larger numbers for the obtuse angles.
This Angles Loop game, by Kevin Wilda, is a class favorite. Print and cut out 24 cards on cardstock. Pass out cards, give students time to measure their angle and then play! “I have, Who has?” Download it FREE here!
Finally, I asssess my students’ understanding of measuring angles in a digital format because that’s how the they’ll be assessed on our end of the yealy state assessment.
Students use protractors to measure angles. Some are lines up on the zero, but some require subtraction. They’ll also find the measurement of angles by subtracting from an 180 degree line and will estimate the degrees of angles.
Students will add, subtract, multiply, divide, and even estimate to find the measurement of angles in a circle.
Remember, the key to mastering measurement of angles is practice, so make your practice sessions as fun and engaging as possible.
