This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through 1/360 of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is 360 degrees, so a one-degree angle (1°) turns through 1/360 of the circle, and any angle can be measured by counting how many one-degree angles it contains. An angle that is 1/12 of the circle corresponds to (1/12) × 360° = 30°. Choice B is correct because 1/12 × 360° = 30°, demonstrating understanding that angle measure is fundamentally defined by the fraction of a circle through which the angle turns. Choice A represents inverting the fraction (12°), which happens when students miscalculate the fraction-degree conversion. To help students: Use a circular model (like a clock or pizza) to show that a full circle has 360°. Emphasize the definition: a one-degree angle (1°) is 1/360 of a circle—this is why we have 360° in a full circle. Show benchmark fractions: 1/2 circle = 180°, 1/4 circle = 90°, 1/8 circle = 45°. Draw circles with rays from center to edge, shading the arc between rays to visualize the fraction. Use clock faces: 12 hours on a clock, so each hour = 1/12 circle = 30°. Watch for: students who think 1° = 1/100 (percentage confusion), students who confuse 180° (half circle) with 360° (full circle), and students who don't connect the fraction of the circle to the angle measure.

This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through 1/360 of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is 360 degrees, so a one-degree angle (1°) turns through 1/360 of the circle, and any angle can be measured by counting how many one-degree angles it contains. An angle that is 1/2 of the circle corresponds to 1/2 × 360° = 180°. Choice C is correct because 1/2 × 360° = 180°, which demonstrates understanding that angle measure is fundamentally defined by the fraction of a circle through which the angle turns. Choice A represents using 1/4 instead of 1/2 (90°), which happens when students confuse half with quarter or miscalculate the fraction. To help students: Use a circular model (like a clock or pizza) to show that a full circle has 360°. Emphasize the definition: a one-degree angle (1°) is 1/360 of a circle—this is why we have 360° in a full circle. Show benchmark fractions: 1/2 circle = 180°, 1/4 circle = 90°, 1/8 circle = 45°. Draw circles with rays from center to edge, shading the arc between rays to visualize the fraction. Use clock faces: 12 hours on a clock, so each hour = 1/12 circle = 30°. Watch for: students who think 1° = 1/100 (percentage confusion), students who confuse 180° (half circle) with 360° (full circle), and students who don't connect the fraction of the circle to the angle measure.

This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through 1/360 of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is 360 degrees, so a one-degree angle (1°) turns through 1/360 of the circle, and any angle can be measured by counting how many one-degree angles it contains. A one-degree angle represents 1/360 of a complete rotation. Choice B is correct because 1° = 1/360 by definition. Choice D represents using 1/100 instead of 1/360 (percentage confusion), which happens when students think of percentages (100) instead of degrees (360). To help students: Use a circular model (like a clock or pizza) to show that a full circle has 360°. Emphasize the definition: a one-degree angle (1°) is 1/360 of a circle—this is why we have 360° in a full circle. Show benchmark fractions: 1/2 circle = 180°, 1/4 circle = 90°, 1/8 circle = 45°. Draw circles with rays from center to edge, shading the arc between rays to visualize the fraction. Use clock faces: 12 hours on a clock, so each hour = 1/12 circle = 30°. Watch for: students who think 1° = 1/100 (percentage confusion), students who confuse 180° (half circle) with 360° (full circle), and students who don't connect the fraction of the circle to the angle measure.

This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through 1/360 of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is 360 degrees, so a one-degree angle (1°) turns through 1/360 of the circle, and any angle can be measured by counting how many one-degree angles it contains. An angle that is 1/2 of the circle corresponds to 1/2 × 360° = 180°. Choice C is correct because 1/2 × 360° = 180°, demonstrating understanding that angle measure is fundamentally defined by the fraction of a circle through which the angle turns. Choice A represents confusing 1/2 with 1/4 (90°), which happens when students miscalculate the fraction-degree conversion. To help students: Use a circular model (like a clock or pizza) to show that a full circle has 360°. Show benchmark fractions: 1/2 circle = 180°, 1/4 circle = 90°, 1/8 circle = 45°. Emphasize the definition: a one-degree angle (1°) is 1/360 of a circle—this is why we have 360° in a full circle.

This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through 1/360 of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is 360 degrees, so a one-degree angle (1°) turns through 1/360 of the circle, and any angle can be measured by counting how many one-degree angles it contains. A one-degree angle represents 1/360 of a complete rotation. Choice A is correct because 1° = 1/360 by definition, demonstrating understanding that angle measure is fundamentally defined by the fraction of a circle through which the angle turns. Choice D represents using 1/100 (percentage confusion), which happens when students think of percentages (100) instead of degrees (360). To help students: Use a circular model (like a clock or pizza) to show that a full circle has 360°. Emphasize the definition: a one-degree angle (1°) is 1/360 of a circle—this is why we have 360° in a full circle. Show benchmark fractions: 1/2 circle = 180°, 1/4 circle = 90°, 1/8 circle = 45°. Draw circles with rays from center to edge, shading the arc between rays to visualize the fraction. Use clock faces: 12 hours on a clock, so each hour = 1/12 circle = 30°. Watch for: students who think 1° = 1/100 (percentage confusion), students who confuse 180° (half circle) with 360° (full circle), and students who don't connect the fraction of the circle to the angle measure.

This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through 1/360 of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is 360 degrees, so a one-degree angle (1°) turns through 1/360 of the circle, and any angle can be measured by counting how many one-degree angles it contains. A full circle represents 360° of rotation. Choice C is correct because full circle = 360°, demonstrating understanding that angle measure is fundamentally defined by the fraction of a circle through which the angle turns. Choice A represents using 100 instead of 360 (percentage confusion), which happens when students think of percentages (100) instead of degrees (360). To help students: Use a circular model (like a clock or pizza) to show that a full circle has 360°. Emphasize the definition: a one-degree angle (1°) is 1/360 of a circle—this is why we have 360° in a full circle. Show benchmark fractions: 1/2 circle = 180°, 1/4 circle = 90°, 1/8 circle = 45°. Draw circles with rays from center to edge, shading the arc between rays to visualize the fraction. Use clock faces: 12 hours on a clock, so each hour = 1/12 circle = 30°. Watch for: students who think 1° = 1/100 (percentage confusion), students who confuse 180° (half circle) with 360° (full circle), and students who don't connect the fraction of the circle to the angle measure.

This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through 1/360 of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is 360 degrees, so a one-degree angle (1°) turns through 1/360 of the circle, and any angle can be measured by counting how many one-degree angles it contains. A one-degree angle represents 1/360 of a complete rotation. Choice C is correct because 1° = 1/360 by definition. Choice A represents using 1/100 instead of 1/360 (percentage confusion), which happens when students think of percentages (100) instead of degrees (360). To help students: Use a circular model (like a clock or pizza) to show that a full circle has 360°. Emphasize the definition: a one-degree angle (1°) is 1/360 of a circle—this is why we have 360° in a full circle. Show benchmark fractions: 1/2 circle = 180°, 1/4 circle = 90°, 1/8 circle = 45°. Draw circles with rays from center to edge, shading the arc between rays to visualize the fraction. Use clock faces: 12 hours on a clock, so each hour = 1/12 circle = 30°. Watch for: students who think 1° = 1/100 (percentage confusion), students who confuse 180° (half circle) with 360° (full circle), and students who don't connect the fraction of the circle to the angle measure.

This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through 1/360 of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is 360 degrees, so a one-degree angle (1°) turns through 1/360 of the circle, and any angle can be measured by counting how many one-degree angles it contains. A full circle represents 360° of rotation. Choice C is correct because full circle = 360°. Choice A represents using 100 instead of 360 (percentage confusion), which happens when students think of percentages (100) instead of degrees (360). To help students: Use a circular model (like a clock or pizza) to show that a full circle has 360°. Emphasize the definition: a one-degree angle (1°) is 1/360 of a circle—this is why we have 360° in a full circle. Show benchmark fractions: 1/2 circle = 180°, 1/4 circle = 90°, 1/8 circle = 45°. Draw circles with rays from center to edge, shading the arc between rays to visualize the fraction. Use clock faces: 12 hours on a clock, so each hour = 1/12 circle = 30°. Watch for: students who think 1° = 1/100 (percentage confusion), students who confuse 180° (half circle) with 360° (full circle), and students who don't connect the fraction of the circle to the angle measure.

This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through $1/360$ of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is $360^\circ$, so a one-degree angle ($1^\circ$) turns through $1/360$ of the circle, and any angle can be measured by counting how many one-degree angles it contains. An angle that is $120/360$ of the circle corresponds to ($120/360$) × $360^\circ$ = $120^\circ$. Choice A is correct because converting fraction to degrees: $120/360$ × $360^\circ$ = $120^\circ$. Choice B represents using $1/4$ instead of $120/360$ ($90^\circ$), which happens when students miscalculate the fraction or approximate incorrectly. To help students: Use a circular model (like a clock or pizza) to show that a full circle has $360^\circ$. Emphasize the definition: a one-degree angle ($1^\circ$) is $1/360$ of a circle—this is why we have $360^\circ$ in a full circle. Show benchmark fractions: $1/2$ circle = $180^\circ$, $1/4$ circle = $90^\circ$, $1/8$ circle = $45^\circ$. Draw circles with rays from center to edge, shading the arc between rays to visualize the fraction. Use clock faces: 12 hours on a clock, so each hour = $1/12$ circle = $30^\circ$. Watch for: students who think $1^\circ$ = $1/100$ (percentage confusion), students who confuse $180^\circ$ (half circle) with $360^\circ$ (full circle), and students who don't connect the fraction of the circle to the angle measure.

This question tests 4th grade understanding that an angle is measured with reference to a circle, where a one-degree angle turns through 1/360 of a circle (CCSS.4.MD.5.a). Angles are measured by considering a circle with its center at the vertex (common endpoint of the rays). The angle measure is determined by the fraction of the circular arc between where the two rays intersect the circle. A full circle is 360 degrees, so a one-degree angle (1°) turns through 1/360 of the circle, and any angle can be measured by counting how many one-degree angles it contains. An angle that is 1/6 of the circle corresponds to 1/6 × 360° = 60°. Choice C is correct because 1/6 × 360° = 60°, which demonstrates understanding that angle measure is fundamentally defined by the fraction of a circle through which the angle turns. Choice D represents using 1/4 instead of 1/6 (90°), which happens when students confuse different fractions or miscalculate. To help students: Use a circular model (like a clock or pizza) to show that a full circle has 360°. Emphasize the definition: a one-degree angle (1°) is 1/360 of a circle—this is why we have 360° in a full circle. Show benchmark fractions: 1/2 circle = 180°, 1/4 circle = 90°, 1/8 circle = 45°. Draw circles with rays from center to edge, shading the arc between rays to visualize the fraction. Use clock faces: 12 hours on a clock, so each hour = 1/12 circle = 30°. Watch for: students who think 1° = 1/100 (percentage confusion), students who confuse 180° (half circle) with 360° (full circle), and students who don't connect the fraction of the circle to the angle measure.