4.MD.5a: Understanding Angle Measurements in Relation to Circles

Grade: 4th Grade

Domain: MD: Measurement and Data

Standard Description

An angle is measured with reference to a circle with its center at the common endpoint of the rays, by considering the fraction of the circular arc between the points where the two rays intersect the circle. An angle that turns through 1/360 of a circle is called a “one-degree angle,” and can be used to measure angles.

Domain Description

Understand the relative sizes of measurement units such as km, m, cm; kg, g; lb, oz.; l, ml; hr, min, sec and know how to convert them. For instance, know that 1 ft equals 12 inches, so a 4 ft snake is 48 in. Create a conversion table for feet and inches like (1, 12), (2, 24), (3, 36), ...

Utilize the four operations to solve problems involving distances, time intervals, liquid volumes, weight of objects, and money. This can include converting measurements from a larger to a smaller unit, and representing measurement quantities using number line diagrams.

Apply the area and perimeter formulas for rectangles to solve real-world and mathematical problems. For instance, find the width of a room given the area of the floor and the length.

Create a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8). Use this to solve problems involving addition and subtraction of fractions. For example, find and interpret the difference in length between the longest and shortest specimens in an insect collection.