Class 4 Maths Chapter 2 Summary Notes PDF Download
Long and Short :
The long and short are the adjectives or parameters to measure something.
The two most important terms used while calculating or measuring something are “long and short”.
These are the scales of measurement to measure distance , time , height etc.
Long is the word used when something measures very big. Long refers to a large value whenever something is measured.
Short can be said as opposite to long. It refers to something that measures less or not so big.
Length of Pencils Comparison
The above figure shows the length of two pencils.
Yellow pencil is 11 units long.
Green pencil is 9 units long.
As we know that 9 is smaller than 11. If we compare the lengths of these two pencils, then we can say that, yellow pencil is long and green pencil is short.
Length and Distance:
Distance is nothing but measurement of a length of some object, say, how long the road is, gives its distance. Distance is how far apart objects are, such as two cities or two points.
Units of Length and Distance : There are several units of distance and most commonly used ones are Millimetres , centimetres, metres ,Kilometres etc.
Millimetres: Millimetres is a unit of length in the metric system. A millimetre is one thousandth of a metre. It is represented by ‘mm’.
Representation of cm and mm on a Scale
Centimetres: Centimetres a unit of length in the metric system, equal to one hundredth of a metre. It is denoted by ‘cm’
Representation of cm on a Scale
Metres: Metres basic or fundamental unit of length in the metric system. It is denoted by ‘m’.
Kilometres: Kilometres is a unit of length in the metric system, it is equal to one thousand metres. It is denoted by Km.
Solved Example 1: Look for things in your surroundings that are
(i) About 10 centimetres long
(ii) Between 10 and 20 centimetres long
(iii) Less than 1 cm long.
Ans:
i. The things that are about 10 cm long are:
Tea Mug , Cell phones , Hair comb etc
ii. The things that are about 10 cm and 20 cm long are:
Soft Drinks bottles , Dinner forks , Carrots etc.
iii. The things that are less than 1 cm long are:
Watermelon seed , a single piece of rice , a piece of daal etc.
Solved Example 2: Convert the following into Metres
i. 700 cm
ii. 3000 mm
iii. 2 km
Ans: To convert the following into metres we need to scale between the following and metres.
i. 700 cm
We know that 100 cm = 1 m , therefore 700 cm can be obtained by multiplying 7 to both sides. i.e
$Rightarrow 7 (100 cm) = 7 (1 m) $
$Rightarrow 700 cm = 7 m.$
ii. 3000 mm
We know that 1000 mm = 1 m , therefore 3000 mm can be obtained by multiplying 3 to both sides. i.e
$Rightarrow 3 (1000 mm) = 3 (1 m) $
$Rightarrow 3000 mm = 3 m.$
iii. 2 km
We know that 1000 m = 1 km , therefore 2000 m can be obtained by multiplying 2 to both sides. i.e
$Rightarrow 2 (1000 m) = 2 (1 km) $
$Rightarrow 2 km = 2000 m.$
How Many ?( The Art of Finding Total)
How many simply means “what number of”.
It is usually used to find a multiple of one thing with respect to another.
For example, how many times Chennai Super Kings have won the IPL? Here winning IPL is the event and we are supposed to find the multiple of it.
If we say Chennai have won the IPL 4 times , the event winning IPL is multiplied by 4.
Solved Examples 1: What is the length of rope , if the rope is 6 arms of Roopa and Roopa’s arm is 25 cm long?
Ans: Given , Length of Roopa’s arm = 25 cm.
The rope is 6 arms , which means 6 times the length of the arm.
Therefore , the length of rope = $ 6\times 25 = 150 cm$.
Length of the rope is 150 cm.
Long and Short used for Comparison:
In order to compare the length of two quantities , we need to find the length of each of them ( that is how long or short they are).
For example, to say which is longer, thumb or middle finger? First we need to measure them and we can conclude which one is longer.
So this goes without saying that the length of the middle finger is longer than the thumb.
Interesting fact: For most people, their arm span is about equal to their height. Mathematicians say the arm span to height ratio is one to one: your arm span goes once into your height.
Arm Span of a Human Being
Solved Examples 1: Who has a longer hand , a new born baby or an adult ?
Ans: It is quite evident and clear that an adult definitely has longer hands compared to a new born baby.
Practice Questions:
1. The distance between two cities is measured in ?
2. Name any four objects that are 1 m long ?
Answers:
1. Kilometres
2. Guitars, yard sticks , Baseball bats , Doorknob Height etc.,
Conclusion
Vedantu's Long and Short Class 4 Notes for CBSE Maths Chapter 2 offer a valuable resource for young learners. Providing a comprehensive and concise overview of the subject, these notes cater to the specific needs of Class 4 students. The availability of a free PDF download makes it accessible to all, promoting inclusivity in education. Vedantu's commitment to delivering high-quality educational materials is evident through these notes, aiding students in grasping mathematical concepts effectively. By offering both long and short versions, students can choose the format that suits their learning style best. Overall, Vedantu's Class 4 Maths Chapter 2 notes serve as an excellent aid for young learners on their academic journey.
Related Study Materials for Class 4 Maths Chapter 2
CBSE Class Chapter-wise Class 4 Maths Chapter 1 Revision Notes
Related Study Material Links for Class 4 Maths
FAQs on Long and Short Class 4 Maths Chapter 2 CBSE Notes - 2025-26
1. What are the main concepts to summarise in the Class 4 chapter 'Long and Short'?
For a quick revision of Chapter 2, 'Long and Short', focus on these key concepts:
- Understanding Length: Identifying which objects are long and which are short.
- Standard Units: Learning the basic standard units of length, which are centimetres (cm), metres (m), and kilometres (km).
- Measurement: Using a ruler or scale to measure the length of objects accurately.
- Conversion: Understanding the simple relationship between metres and centimetres (1 m = 100 cm).
- Estimation: Making a sensible guess about the length of an object before measuring it.
2. What is the simple rule for converting metres (m) to centimetres (cm) for a quick revision?
The key rule to remember for revision is: 1 metre is equal to 100 centimetres. To convert metres to centimetres, you multiply the number of metres by 100. For example, 3 metres is 3 x 100 = 300 centimetres. To convert centimetres to metres, you can think of grouping them in hundreds; for instance, 500 cm is equal to 5 m.
3. What is the key summary of how to measure length correctly using a scale or ruler?
To correctly measure length with a ruler, follow this summary:
- Place the '0' mark of the ruler exactly at the starting point of the object you want to measure.
- Keep the ruler straight along the edge of the object.
- Read the number on the ruler that aligns with the object's ending point.
- This number tells you the length of the object in centimetres (cm).
4. Why is it better to use a standard unit like a centimetre instead of non-standard units like a handspan for measuring things?
It is better to use a standard unit like a centimetre (cm) because everyone in the world agrees on its exact length. A handspan is a non-standard unit because everyone's hand is a different size. If you and your friend measure the same table with your handspans, you might get different answers. Using a standard unit like a centimetre ensures that the measurement is always the same, no matter who measures it.
5. How do you decide which unit of length—centimetres, metres, or kilometres—is best for describing different objects or distances?
You can decide which unit to use by thinking about the size of what you are measuring. Here is a simple guide:
- Use centimetres (cm) for small objects, like the length of a pencil, an eraser, or a book.
- Use metres (m) for longer things, like the length of a room, the height of a door, or a saree.
- Use kilometres (km) for very long distances, like the distance between two cities or the length of a river.
6. Beyond just measuring, what is the importance of 'estimating' length in our daily lives?
Estimating length is important because it helps us make quick, smart guesses without needing a tool. For example, by estimating, you can quickly figure out if a new table will fit in your room, if a thread is long enough to tie a box, or roughly how far away your school is. It's a useful mental math skill that helps in planning and problem-solving every day.
7. How does understanding conversion between units help in solving word problems about distance?
Understanding conversion is crucial for solving word problems because sometimes the information is given in different units. For example, a problem might mention a distance in metres and ask for the answer in kilometres, or vice-versa. To solve it correctly, you must first convert all measurements to the same unit. This ensures your addition or subtraction is accurate, helping you find the correct total distance or difference in length.
