Activating Strategy

Make a 4-square page in our math journals to answer Warm-Up questions using SLIDE 96.

The United States uses customary units to measure the length of objects. Customary units of length are inches, feet, and yards. You may have heard of these units daily, like when measuring your height or in sports. Other countries in the world use metric units to measure length.  

Today, we will explore the metric measurement of length to learn about the relative size of metric units used to measure length. The metric units for length that we will explore in 4th grade are centimeters, meters, and kilometers.

Let’s start by looking at household objects that will help us learn about the relative size of centimeters, meters, and kilometers.

Centimeters: Centimeters are the metric units we use to measure short objects. Centimeters are abbreviated with “cm.”

Meters: Meters are the units we use when measuring items with a longer length or distance of objects.  There are 100 centimeters in one meter. Let’s look at some items that would be about one meter. Meters are abbreviated with “m.”  

Kilometers: We use metric units to measure long distances. “Kilo” means 1,000, so a kilometer technically means 1,000 meters. There are 1,000 meters in one kilometer, abbreviated as “km.”

A local artist painted two murals. 

The first mural is 5  1/2 meters long, and the second is 5  2/5 centimeters long. 

Which mural is longer? (1 meter = 100 centimeters)

After reading the problem carefully, I will have to compare meters to centimeters. The length of the first mural is 5 ½ meters. We need a two-column table to determine how many centimeters are in 5 ½ meters.  I know 100 centimeters are in one meter, so I can use this information to help me determine how many centimeters are in 5 ½ meters.

We know 1 meter equals 100 centimeters, so ½ meter equals 50 centimeters. We can continue tracking our equivalencies using a two-column table to see that 5 ½ meters equals 550 centimeters.

Using a two-column table, we determined that the first mural is 5 ½ meters or 550 centimeters and the second mural is 525 centimeters. 

Therefore, the first mural is longer than the second mural because 550 centimeters is greater than 525 centimeters, or 550 cm > 525 cm. 

Guided Practice

Okay, mathematicians, it's your turn to show what you know!  

Practice with me:

Now, I would like for you to give this a try.

The Peachtree Road Race is the world’s largest 10-kilometer race, held each July 4th in Atlanta. If participants run ½ km to warm up for the race, how many total meters is the Peachtree Road Race, including the warm-up?  

(1 kilometer = 1000 meters)

Remember, when working with metric units of length, we measure small objects using centimeters, larger objects using meters, and larger distances using kilometers. We can also record metric length equivalents using a two-column chart to express larger units within the same measurement system and smaller units in terms of larger units within the same measurement system.

Small Group Practice:

Hailey measured the length of the hallway at her house. She said it measured 700 centimeters. Kenneth said the hallway is a long measurement, and measuring it with longer units like meters would be easier.  If Kenneth measured the hallway using meters, what would the measurement of the hallway be in meters?

(1 meter = 100 centimeters)

Independent Task

1. FRECKLE - Complete THREE Freckle Assignments each week. DUE FRIDAY. Your HIGHEST score in Targeted Practice is your weekly math grade - Click HERE for Freckle website

• GRADED Targeted Practice - Current skill (5 questions; Score Goal=80% or higher)

• Fact Practice - Multiplication Fact Practice

• Adaptive Practice - At YOUR level

2. iREADY Math - Complete 30 minutes at your level each week