Go Math! Grade 4, Chapter 11: Angles
In this unit, your child learns how angles are measured. They connect angles to fractions of a circle, measure and draw angles in degrees with a protractor, and join and separate angles to find unknown measures. It builds on last unit's work with lines and shapes, and leads into comparing measurement units.
By Robert “Bobby” BarnettMath teacher, parent, and founder of Bobby’s Math Club
What is my child learning in Chapter 11?
- Relating angles to fractions of a circle, so 1/4 of a turn is 90 degrees and 1/2 of a turn is 180. Learn more: What angles are and how degrees measure them
- Measuring angles with a protractor by choosing the right scale, and drawing angles like 35 or 140 degrees. Learn more: Measuring and drawing angles with a protractor
- Joining and separating angles, and writing an equation like 75 + x = 180 to find the unknown angle. Learn more: Adding angles together to find a missing one
Sample questions to try together
These are real questions from our practice. Tap the speaker to hear one read aloud, or the light bulb for a hint, and talk about the answer together.
Question 1 of 3
An angle measures 60°. How many one-degree angles does it turn through?
- 300
- 60
- 6
How you can help
- Fold a paper plate in half and in half again, then open it. Show that each quarter's corner at the center is 90 degrees, and that four make a full 360-degree turn.
- Look at a slice of pizza together. Ask your child to guess the angle at its point, and whether it is more or less than 90 degrees.
- Use a clock at bedtime. Ask how big the angle between the hands is at 3:00, then at 1:00, and how many 1:00 angles fit inside the 3:00 one.
Where kids can get stuck
- Reading the wrong scale on a protractor, so a 40-degree angle gets recorded as 140.
- Struggling to connect a quarter turn to 90 degrees and a half turn to 180.
- Measuring the drawing with a protractor instead of using the given angle numbers, and landing a few degrees off.
Practice makes perfect
Bobby's Math Club has practice problems that adapt to your child’s level, each with a detailed explanation and an easy-to-follow video, so your child can build confidence in these skills one step at a time.
Words your child will hear
- angle
- The figure made by two rays that share an endpoint.
- vertex
- The point where two rays or two sides meet.
- degree
- The unit for measuring angles; a full turn is 360 degrees.
- protractor
- A half-circle tool marked in degrees, used to measure and draw angles.
- acute angle
- An angle smaller than a right angle, measuring less than 90 degrees.
- obtuse angle
- An angle larger than a right angle but smaller than 180 degrees.
- straight angle
- An angle that measures 180 degrees and looks like a straight line.
Ready to build your child’s confidence with angle measurement?
In Bobby's Math Club, your child practices these skills at just the right level, with a hint when they need one, a clear explanation after every question, and kid-friendly videos. Unlimited practice is free.
Join the club
Written by Robert “Bobby” Barnett
Bobby is an award-winning math teacher, the author of Meet Every Learner’s Needs, and the father of two elementary-school math learners. He uses Bobby’s Math Club with his own kids a few times every week. Learn more or contact Bobby.
Which math standards does Go Math! Grade 4 Chapter 11 cover?
Go Math! Grade 4 Chapter 11 covers these math standards. Each one links to what it means, sample questions, and teaching strategies.
For teachers: Unit names and order vary between editions and districts, so your school’s own materials have the exact sequence. Learn how Bobby's Math Club can help your students grow.