Comparing Lengths
Comparing lengths means finding out which object is longer, shorter, or if two objects are the same length. In Class 2, we compare lengths by measuring with a ruler and finding the difference.
We use words like longer, shorter, taller, and same length when we compare.
What is Comparing Lengths - Class 2 Maths (Measurement (Grade 2))?
When we compare lengths, we look at two or more objects and find out:
- Which one is longer (has more length)
- Which one is shorter (has less length)
- How much longer or shorter one is than the other
Difference in length = Longer length − Shorter length
Comparing Lengths Formula
Steps to compare lengths:
- Measure the length of the first object in cm
- Measure the length of the second object in cm
- Compare the two numbers
- The bigger number means the longer object
- Subtract to find how much longer or shorter
Solved Examples
Example 1: Example 1: Two Pencils
Question: Ria's pencil is 14 cm long. Aman's pencil is 9 cm long. Which pencil is longer? By how much?
Think:
- Ria's pencil = 14 cm
- Aman's pencil = 9 cm
- 14 is more than 9, so Ria's pencil is longer
- Difference = 14 − 9 = 5 cm
Answer: Ria's pencil is longer by 5 cm.
Example 2: Example 2: Ribbons
Question: Priya has a red ribbon that is 25 cm long and a blue ribbon that is 25 cm long. Compare them.
Think:
- Red ribbon = 25 cm
- Blue ribbon = 25 cm
- Both numbers are the same
Answer: Both ribbons are the same length.
Example 3: Example 3: Comparing Heights
Question: Dev is 120 cm tall. Meera is 115 cm tall. Who is taller? By how much?
Think:
- Dev = 120 cm
- Meera = 115 cm
- 120 > 115, so Dev is taller
- Difference = 120 − 115 = 5 cm
Answer: Dev is taller by 5 cm.
Example 4: Example 4: Three Objects
Question: A crayon is 8 cm, a marker is 13 cm, and a chalk is 6 cm. Arrange them from shortest to longest.
Think:
- Chalk = 6 cm (smallest number)
- Crayon = 8 cm
- Marker = 13 cm (biggest number)
Answer: Shortest to longest: Chalk (6 cm), Crayon (8 cm), Marker (13 cm).
Example 5: Example 5: How Much Shorter?
Question: Aditi's skipping rope is 150 cm long. Kavi's skipping rope is 120 cm long. How much shorter is Kavi's rope?
Think:
- Aditi's rope = 150 cm
- Kavi's rope = 120 cm
- Difference = 150 − 120 = 30 cm
Answer: Kavi's rope is 30 cm shorter than Aditi's rope.
Example 6: Example 6: Comparing in Metres
Question: Rahul's garden is 5 m long. Neha's garden is 3 m long. How much longer is Rahul's garden?
Think:
- Rahul's garden = 5 m
- Neha's garden = 3 m
- Difference = 5 − 3 = 2 m
Answer: Rahul's garden is 2 metres longer.
Example 7: Example 7: Word Problem
Question: Arjun cut a piece of string that is 18 cm long. He needs 25 cm for his craft project. How much more string does he need?
Think:
- String he has = 18 cm
- String he needs = 25 cm
- More needed = 25 − 18 = 7 cm
Answer: Arjun needs 7 cm more string.
Key Points to Remember
- To compare lengths, measure both objects in the same unit (both in cm or both in m).
- The object with the bigger number is longer.
- Subtract to find the difference in length.
- Use words like longer, shorter, taller, and same length.
- You can arrange objects from shortest to longest or longest to shortest.
Practice Problems
- A book is 22 cm long. A notebook is 28 cm long. Which is longer and by how much?
- Meera's braid is 35 cm long. Priya's braid is 42 cm long. How much longer is Priya's braid?
- Three sticks are 10 cm, 15 cm, and 7 cm long. Arrange them from longest to shortest.
- Aman is 118 cm tall. Dev is 125 cm tall. Who is shorter? By how much?
- A red thread is 50 cm. A blue thread is 1 m. Which is longer? (Hint: convert m to cm first.)
- Ria needs 30 cm of ribbon. She has 22 cm. How much more does she need?
Frequently Asked Questions
Q1. How do we compare the lengths of two objects?
Measure both objects using the same unit (cm or m). The object with the bigger number is longer. Subtract to find how much longer.
Q2. What does 'difference in length' mean?
It means how much longer or shorter one object is compared to another. You find it by subtracting the shorter length from the longer length.
Q3. Can we compare lengths in different units?
No. Both objects must be measured in the same unit before comparing. Convert metres to centimetres (or the other way) first.
Q4. What words do we use when comparing lengths?
We use longer, shorter, taller, same length, longest, and shortest when comparing lengths of objects.
Q5. How do I arrange objects by length?
Measure all objects. Write their lengths. Put them in order from smallest number (shortest) to biggest number (longest), or the other way around.
Q6. What if two objects are the same length?
If both objects have the same measurement, we say they are of equal length or the same length. The difference is 0.
