MAFS.3.MD.1.1 Tell and write time to the nearest minute and measure time intervals in minutes. Solve word problems involving addition and subtraction of time intervals in minutes, e.g., by representing the problem on a number line diagram.
MAFS.3.OA.4.8 Solve two-step word problems using the four (addition or subtraction) operations. Represent these problems using equations with a letter (symbol) standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.
In this unit students extend their skills from second grade (telling time to the nearest 5 minutes and understanding A.M./P.M.) to telling time to the minute. Asking students to tell time at various points throughout the day allows students to practice the skill of telling time. Students will use addition/subtraction to solve time problems as well as problems related to elapsed time. It is often difficult for students to keep track of the passing hours on an analog clock because it is circular. Therefore, using number lines can simplify this task. Using a number line allows the students to visualize the circular clock face in a linear way. Exposure to the visual models to help solve elapsed time problems helps students to understand the idea of time intervals.
GCG 1 – Learning Goal: As a mathematician, I will be able to tell and write time to the nearest minute
- Step 1: Tell & record time to the nearest minute using an analog clock
- Step 2: Tell & record time to the nearest minute in multiple ways, for example: 12 minutes after 4, 18 minutes before 7
GCG 2 – Learning Goal: As a mathematician, I will be able to solve problems involving elapsed time
- Step 1: Solve for the end time in word problems
- Step 2: Solve for the start time in word problems
- Step 3: Solve one and two step word problems involving elapsed time