Grade: Grade 3 Subject: Mathematics Unit: Measurement Conversions SAT: ProblemSolving+DataAnalysis ACT: Math

Length Conversions

Did you know that 12 inches equals 1 foot? Or that scientists around the world use meters and centimeters? Learning to convert between different units of length helps us measure everything from tiny insects to giant buildings!

What is Length?

Length Tells Us How Long Something Is!

Length is a measurement that tells us the distance from one end of something to the other. We use different units depending on what we're measuring!

Two Measurement Systems

In the United States, we use two different systems to measure length:

U.S. Customary System

This is what we use every day in America!

  • Inches (in) - for small things
  • Feet (ft) - for medium things
  • Yards (yd) - for bigger things

Example: Your height might be measured in feet and inches!

Metric System

This is used by scientists and most other countries!

  • Centimeters (cm) - for small things
  • Meters (m) - for bigger things

Example: Olympic swimming pools are measured in meters!

Conversion Charts

These charts show how different units relate to each other. Memorize these important facts!

U.S. Customary Length Conversions

Conversion Remember It!
12 inches = 1 foot Like 12 months in a year, 12 inches make a foot!
3 feet = 1 yard A yard is as long as 3 rulers lined up!
36 inches = 1 yard 12 x 3 = 36 (12 inches in each of 3 feet)

Metric Length Conversions

Conversion Remember It!
100 centimeters = 1 meter "Centi" means 100, like 100 cents in a dollar!
1 meter = about 3 feet A meter is a little longer than a yard.
Memory Trick: Think of a ruler! A standard ruler is 12 inches long, which equals 1 foot. If you line up 3 rulers, you get 1 yard!

When to Use Different Units

Choosing the right unit makes measuring easier! Here's when to use each one:

📏
Inches

Use for: Small objects

Pencils, crayons, your hand, small toys, books
📐
Feet

Use for: Medium things

Your height, doors, tables, TV screens, rooms
🏃
Yards

Use for: Larger distances

Football fields, playgrounds, fabric, gardens
🔬
Centimeters

Use for: Precise small measurements

Science experiments, art projects, paper sizes
🏊
Meters

Use for: Larger metric measurements

Swimming pools, running tracks, room sizes

🌍 Real-World Examples

🏈

Football Field
100 yards long

🚪

Door
About 7 feet tall

✏️

New Pencil
About 7 inches long

🏊

Olympic Pool
50 meters long

How to Convert

📏 Inches to Feet

Since 12 inches = 1 foot, divide by 12 to convert inches to feet!

How many feet is 24 inches?

  1. We know: 12 inches = 1 foot
  2. Divide: 24 / 12 = 2
  3. So 24 inches = 2 feet!

Answer: 24 inches = 2 feet

🦶 Feet to Inches

Multiply by 12 to convert feet to inches!

How many inches is 3 feet?

  1. We know: 1 foot = 12 inches
  2. Multiply: 3 x 12 = 36
  3. So 3 feet = 36 inches!

Answer: 3 feet = 36 inches

🏃 Feet to Yards

Since 3 feet = 1 yard, divide by 3 to convert feet to yards!

How many yards is 9 feet?

  1. We know: 3 feet = 1 yard
  2. Divide: 9 / 3 = 3
  3. So 9 feet = 3 yards!

Answer: 9 feet = 3 yards

📐 Yards to Feet

Multiply by 3 to convert yards to feet!

How many feet is 5 yards?

  1. We know: 1 yard = 3 feet
  2. Multiply: 5 x 3 = 15
  3. So 5 yards = 15 feet!

Answer: 5 yards = 15 feet

🔬 Centimeters to Meters

Since 100 centimeters = 1 meter, divide by 100!

How many meters is 300 centimeters?

  1. We know: 100 centimeters = 1 meter
  2. Divide: 300 / 100 = 3
  3. So 300 centimeters = 3 meters!

Answer: 300 cm = 3 meters

📏 Meters to Centimeters

Multiply by 100 to convert meters to centimeters!

How many centimeters is 2 meters?

  1. We know: 1 meter = 100 centimeters
  2. Multiply: 2 x 100 = 200
  3. So 2 meters = 200 centimeters!

Answer: 2 meters = 200 cm

Remember: When going from a SMALLER unit to a BIGGER unit, you DIVIDE. When going from a BIGGER unit to a SMALLER unit, you MULTIPLY!

Interactive Converter

Try converting lengths yourself! Enter a number and see the conversion.

Length Converter Tool

=
12 inches = 1 foot

Practice Problems

Test your conversion skills! Click the correct answer.

Problem 1

How many inches are in 2 feet?

Problem 2

How many feet are in 36 inches?

Problem 3

How many feet are in 4 yards?

Problem 4

How many yards are in 15 feet?

Problem 5

How many centimeters are in 4 meters?

Problem 6

How many meters are in 500 centimeters?

Conversion Challenge

Practice makes perfect! Type your answer and press Enter.

Quick Conversion Quiz!

24 inches = ? feet
Score: 0 / 0

Word Problems

Let's solve some real-life problems using length conversions!

Word Problem 1

Sarah has a ribbon that is 48 inches long. She wants to know how many feet of ribbon she has. How many feet is 48 inches?

Word Problem 2

A football field is 100 yards long. How many feet is that?

Word Problem 3

Miguel measured a worm that was 8 centimeters long. He found another worm that was 12 centimeters long. If he puts them end to end, how many centimeters is that? And how many total meters?

Check Your Understanding

How many inches are in 1 foot?

How many feet are in 1 yard?

How many centimeters are in 1 meter?

Which unit would you use to measure the length of a pencil?

What We Learned

📏

12 in = 1 ft

Twelve inches make one foot.

📐

3 ft = 1 yd

Three feet make one yard.

🔬

100 cm = 1 m

One hundred centimeters make one meter.

🧠

Choose Wisely

Pick the right unit for what you're measuring!

Keep Practicing! The more you practice converting lengths, the easier it becomes. Try measuring things around your house and converting between units!

Next Steps

  • Memorize the key conversions: 12 inches = 1 foot, 3 feet = 1 yard, 100 cm = 1 meter
  • Practice measuring objects at home and converting between units
  • Try the interactive converter to check your work
  • When ready, learn about time conversions in the next lesson!