Recognize angle measure as additive. When an angle is decomposed into non-overlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Solve addition and subtraction problems to find unknown angles on a diagram in real world and mathematical problems, e.g., by using an equation with a symbol for the unknown angle measure.
Measurement Topic
This standard is reported on the report card in these quarters as follows:
4th Grade Students Learning 4th Grade Standards
Quarter 1
Quarter 2
Quarter 3
Quarter 4
Report Card Measurement Topic:Demonstrates understanding of measurement and geometry.
3rd Grade Students Learning 4th Grade Standards
Quarter 1
Quarter 2
Quarter 3
Quarter 4
Report Card Measurement Topic:Demonstrates understanding of measurement, data and geometry.
Learning Targets
Decompose an angle measurement.
Recognize angle measurement as the additive of the decomposed angle.
Solve problems involving unknown angles.
Write an equation with a symbol for an unknown angle measure.
About the Math
Angle measure is additive. If you draw a third array and divide an angle into two smaller angles, the measures of the two smaller angles equal the original angle. Remember to keep in mind, that the three angles all have the same vertex. The two smaller angles share a common ray. The smaller angles do not overlap. You can find an unknown angle measure, if you know the measure of the original angle and one of the smaller angles. Essential vocabulary for this standard includes: angle, degree, and sum. Visit the online dictionaryLinks to an external site. for vocabulary support.
Progression of Standard within Grade 4
This progression informs how to develop the standard within the grade level. This progression is provided by HCPSS Elementary Mathematics.
Progression Throughout Year
Quarter 1
Quarter 2
Quarter 3
Quarter 4
Decompose an angle measurement.
Recognize angle measurement as the additive of the decomposed angle.
Solve problems involving unknown angles.
Write an equation with a symbol for an unknown angle measure.
Determine the unknown whole number in an addition or subtraction equation relating three whole numbers (1.OA.8)
Use facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple equations for an unknown angle in a figure (7.G.B.5)
These tasks can be used with small group or whole group instruction.
Find three different ways you can decompose 90 degrees and sketch the three examples.
Kyle has two angles that equal an acute angle when added together. What could his two angles be?
Sophia drew an acute angle. Rory drew an angle three times larger than Sophia’s angle. What could the measures of the two angles be? Find another solution.
If 3 angles are placed together so that they create a straight line (180 degrees) and one of the angles is obtuse, what are possible angle measurements of the other two angles?
A ramp must be created next to a flight of stairs so that the building is wheelchair accessible. If there are 4 steps in the flight of stairs and the stairs rise to 3 feet above the ground, how could you create a ramp to get to the top? What could be the measurement of the ramp angle? (give students yard sticks, protractors and yarn to help them seek solutions) What factor changes the angle measurement? (length of the ramp)
SLIDE-BASED TASKS
These links are HCPSS created instructional tasks. These tasks are provided in Google slides. These tasks should be used for inspiration and resources, but instruction should start with students having the opportunity to engage with the math first(often involving physical and/or visual models) followed by discussion and explicit instruction to ensure student understanding.
These publications have been provided for each school. They are typically stored in team closets or the media center. Check with your team leader if you cannot find them.
These resource sheets can be used for independent practice, homework, or assessment. They are intended to reinforce procedures and concepts. They should not be used as a source of direct instruction or whole-group practice.
