A focused Grade 4 learning session for One-Degree Angles using visual models, worked examples, strategy guidance, and a short mastery check.
Student goal: I can explain what one degree means and measure angles in degrees.
One-Degree Angles means choosing a model, naming what each number means, and explaining the strategy.
Question: An angle turns through \(40\) one-degree angles. What is the measure of this angle?
Why it works: The measure of an angle equals the number of one-degree angles it turns through, so \(40\) one-degree angles equal \(\mathbf{40\degree}\).
Answer: \(40\degree\)
Question: The angle opens from \(0\degree\) to \(45\degree\). What is its measure?
Answer: \(45\degree\)
Question: Ava's angle measures \(30\degree\). How many one-degree angles does it contain?
Answer: \(30\) one-degree angles
Question: If an angle turns through \(45\) one-degree angles, what is the measure of the angle?
Why it works: If an angle turns through \(n\) one-degree angles, it measures \(n\) degrees, so \(45\) one-degree angles equal \(\mathbf{45\degree}\).
Answer: \(45\degree\)
One-Degree Angles becomes easier when students connect the question to a model, use clear steps, and explain why the answer fits.
Understand the model before choosing the operation.
Use scratch paper. The explanation matters more than simply seeing whether the choice is correct.
If an angle turns through \(45\) one-degree angles, what is the measure of the angle?
Answer B: 45°
If an angle turns through \(n\) one-degree angles, it measures \(n\) degrees, so \(45\) one-degree angles equal \(\mathbf{45°}\).
An angle turns through \(40\) one-degree angles. What is the measure of this angle?
Answer A: 40°
The measure of an angle equals the number of one-degree angles it turns through, so \(40\) one-degree angles equal \(\mathbf{40°}\).
A circle is divided into sections. The section shown contains \(90\) one-degree angles. What is the measure of this angle?
Answer A: 90°
The sector is marked with \(90\) one-degree angle tick marks, so its measure is \(\mathbf{90°}\).
Ming drew an angle. She said it measures 60°. How many one-degree angles does her angle contain?
Answer C: \(60\) one-degree angles
The measure in degrees tells us how many one-degree angles fit in the angle, so 60° means \(\mathbf{60 \text{ one-degree angles}}\).
The angle opens from 0° to 45°. What is its measure?
Answer A: 45°
Counting the one-degree angle marks from 0° to 45° gives us \(\mathbf{45°}\).
Ava's angle measures 30°. How many one-degree angles does it contain?
Answer B: \(30\) one-degree angles
When we say an angle measures 30°, that means it is made of \(\mathbf{30 \text{ one-degree angles}}\).
This is a right angle. How many one-degree angles make a right angle?
Answer C: \(90\) one-degree angles
A right angle opens to form a 90° angle, which means it is turned through \(\mathbf{90 \text{ one-degree angles}}\).
A straight angle is shown above. How many one-degree angles make a straight angle?
Answer B: \(180\) one-degree angles
A straight angle is a 180° angle, meaning it turns through \(\mathbf{180 \text{ one-degree angles}}\).
A full circle is shown with several rays drawn inside. How many degrees are in the full circle?
Answer C: 360°
A full circle is a 360° angle—it turns through \(\mathbf{360 \text{ one-degree angles}}\).
Noah measured an angle and found it has \(75\) one-degree angles. What is the measure of the angle?
Answer A: 75°
Since the angle turns through \(75\) one-degree angles, it measures \(\mathbf{75°}\).
This angle is marked from 0° to 30°. How many one-degree angles does the angle contain?
Answer B: \(30\) one-degree angles
The angle is marked from 0° to 30°, so it contains \(\mathbf{30 \text{ one-degree angles}}\).
