Guided Practice: Measuring Length
📖 Learn
In this lesson, we will practice measuring objects using all the units we have learned: inches, feet, centimeters, and meters.
Review: Measurement Units
- Inches (in) - Small units for measuring short objects like pencils and books
- Feet (ft) - Larger units; 12 inches = 1 foot
- Centimeters (cm) - Small metric units for measuring short objects
- Meters (m) - Larger metric units; 100 centimeters = 1 meter
Steps for Measuring
- Choose the right tool: Use a ruler for small objects, a yardstick or meter stick for larger objects.
- Line up the object: Place one end of the object at the zero mark.
- Read the measurement: Look at where the other end of the object lines up on the ruler.
- Write your answer: Include the number and the unit (in, ft, cm, or m).
💡 Examples
Example 1: Measuring a Crayon
A crayon is placed next to a ruler. The crayon starts at 0 and ends at 3 inches.
Answer: The crayon is 3 inches long.
Example 2: Measuring a Jump Rope
Maria uses a meter stick to measure her jump rope. It measures 2 meters long.
Answer: The jump rope is 2 meters long.
Example 3: Choosing the Right Unit
Which unit would you use to measure the length of your classroom?
Answer: You would use feet or meters because a classroom is a large space.
✏️ Practice
Try these 10 practice problems. Think carefully about each one!
1. A marker is 15 centimeters long. How many centimeters is that?
Show Answer
15 centimeters (the answer is already given in centimeters!)
2. Sam's desk is 2 feet wide. How many inches is that?
Show Answer
24 inches (2 feet x 12 inches = 24 inches)
3. Which is longer: 1 meter or 50 centimeters?
Show Answer
1 meter is longer (1 meter = 100 centimeters, which is more than 50 centimeters)
4. A book is 8 inches tall. Is this shorter or taller than 1 foot?
Show Answer
Shorter (1 foot = 12 inches, and 8 is less than 12)
5. What unit would you use to measure the length of an ant?
Show Answer
Centimeters (or millimeters) - ants are very small!
6. A swimming pool is 25 meters long. Could you measure this with a small ruler?
Show Answer
No, a swimming pool is too long for a small ruler. You would need a long tape measure or meter stick.
7. Emma measured her pencil. It was 7 inches. Her eraser was 2 inches. How much longer is the pencil than the eraser?
Show Answer
5 inches longer (7 - 2 = 5)
8. A door is about 7 feet tall. Is this more or less than 2 meters?
Show Answer
More than 2 meters (7 feet is about 2.1 meters)
9. Put these in order from shortest to longest: 1 foot, 10 centimeters, 1 meter
Show Answer
10 centimeters, 1 foot, 1 meter (10 cm is about 4 inches; 1 foot is about 30 cm; 1 meter is 100 cm)
10. Jake measured his toy car as 12 centimeters. Lily measured the same car and got 5 inches. Can both be correct?
Show Answer
Yes! They used different units. 12 centimeters is about 5 inches, so both measurements are correct.
✅ Check Your Understanding
Answer these questions to see how well you understand measurement.
- How many inches are in 1 foot?
- How many centimeters are in 1 meter?
- Would you use inches or feet to measure a basketball court?
- Why is it important to start measuring at the zero mark?
Show Answers
- 12 inches
- 100 centimeters
- Feet (or meters) - a basketball court is very long
- If you don't start at zero, your measurement will be wrong - it will be too big or too small
🚀 Next Steps
- Practice measuring objects at home using a ruler
- Try to estimate lengths before you measure them
- Move on to Word Problems to apply your measurement skills