Measuring Length: Inches and Centimeters
Practice choosing units, reading rulers, and comparing lengths
Measuring Length: Inches and Centimeters
Practice choosing units, reading rulers, and comparing lengths
Math - Grade 2-3
- 1
A pencil is 7 inches long. Write the length of the pencil using a number and a unit.
The pencil is 7 inches long. - 2
A crayon measures 9 centimeters long. Is centimeters a good unit to measure a crayon? Explain.
Centimeters are useful for measuring small objects.
Centimeters is a good unit to measure a crayon because a crayon is a small object. - 3
Look at the ruler. The paper clip starts at 0 centimeters and ends at 4 centimeters. How long is the paper clip?
The paper clip is 4 centimeters long because it starts at 0 and ends at 4 on the centimeter ruler. - 4
Which unit would you use to measure the length of a classroom door: inches or centimeters? Explain your choice.
Think about which unit would take fewer marks to measure a large object.
Inches would be a better choice because a classroom door is a larger object and inches are longer than centimeters. - 5
A toy car is 5 inches long. A toy truck is 8 inches long. Which toy is longer, and how much longer is it?
The toy truck is longer. It is 3 inches longer than the toy car because 8 - 5 = 3. - 6
Look at the ruler. The marker starts at 1 inch and ends at 6 inches. How long is the marker?
If an object does not start at 0, subtract the starting number from the ending number.
The marker is 5 inches long because 6 - 1 = 5. - 7
Circle the shorter length: 12 centimeters or 12 inches. Explain how you know.
12 centimeters is shorter than 12 inches because one inch is longer than one centimeter. - 8
A ribbon is 10 centimeters long. You cut off 3 centimeters. How many centimeters of ribbon are left?
Subtract the part that was cut off from the starting length.
There are 7 centimeters of ribbon left because 10 - 3 = 7. - 9
Look at the line segment. It begins at 0 centimeters and ends at 6 centimeters. What is the length of the line segment?
The line segment is 6 centimeters long because it begins at 0 and ends at 6. - 10
Choose the best estimate for the length of a toothbrush: 7 inches or 7 feet. Explain your answer.
Feet are used for much longer lengths than inches.
7 inches is the best estimate because a toothbrush is small enough to hold in your hand. - 11
A book is 11 inches tall. A notebook is 9 inches tall. How much taller is the book than the notebook?
The book is 2 inches taller than the notebook because 11 - 9 = 2. - 12
Look at the two strips. Strip A is 8 centimeters long. Strip B is 5 centimeters long. What is their total length if they are placed end to end?
End to end means you add the lengths.
The total length is 13 centimeters because 8 + 5 = 13. - 13
Measure a real eraser with a ruler. Write its length in centimeters. If you do not have an eraser, use an object about the same size.
Answers will vary. A reasonable answer might be that the eraser is about 4 centimeters long. - 14
Look at the bug on the ruler. It starts at 2 centimeters and ends at 7 centimeters. How long is the bug?
Count the spaces between the numbers, not just the number marks.
The bug is 5 centimeters long because 7 - 2 = 5. - 15
Mia measured a spoon as 15 centimeters long. Leo measured the same spoon as 6 inches long. Can both measurements be reasonable? Explain.
A centimeter is shorter than an inch, so it takes more centimeters to measure the same length.
Both measurements can be reasonable because inches and centimeters are different units. The same object can have different numbers when measured in different units.