CBSE Class 3 Mathematics NCERT Solutions: Chapter 4 - Long and Short

To find the difference in length between your arm and your mother's arm, you would first need to measure both using a measuring tape or a ruler. Let's assume you measured your arm to be 40 centimetres long and your mother's arm to be 60 centimetres long. The difference would be calculated by subtracting the shorter length from the longer length: 60 cm - 40 cm = 20 cm. Therefore, your mother's arm is 20 centimetres longer than yours. The specific difference will depend on your actual measurements.

To determine the number of steps Doiji will take to cross the road, we need to consider the width of the road and the length of Doiji's steps. If Doiji takes steps of a certain size, the total number of steps will depend on how wide the road is. Based on the provided information, Doiji may cross the road in five steps. This suggests that the road is of a moderate width, and Doiji's steps are large enough to cover it in a small number of steps.

To find out how many cups can be placed in a line on the table, you would need to measure the length of the table and the width of one cup. Then, you would divide the length of the table by the width of the cup. For example, if the table is 60 centimetres long and each cup is 6 centimetres wide, you could place 60 cm / 6 cm = 10 cups in a line. As per the information given, ten cups can be placed in a line on this table.

To determine how many pots are needed to reach the tree branch, we need to know the height of the tree branch and the height of each pot. If the pots are stacked one on top of the other, the total height of the stacked pots should equal the height of the tree branch. For instance, if the tree branch is 50 cm high and each pot is 10 cm high, you would need 50 cm / 10 cm = 5 pots. The problem states that five pots can be placed to reach the tree branch, implying the combined height of five pots matches the branch's height.

To figure out how many shirts can be hung on a wire, you need to consider the length of the wire and the space each shirt takes up when hung. If the wire is long enough, you can hang multiple shirts side-by-side. The solution indicates that four shirts can be hung on this wire. This suggests that the wire has a specific length that accommodates four shirts comfortably without them being too crowded.

This statement provides a measurement for a common object. A matchstick is observed to have a length of 4 centimetres. This helps in understanding the scale of a centimetre by relating it to a familiar item.

This statement describes the dimensions of a die. It indicates that the length of each side of the die is 1 centimetre. This means the die is a cube with each edge measuring 1 cm.

This statement gives the length of a lizard as 13 centimetres. This measurement helps to visualize the size of a lizard relative to the unit of a centimetre, showing it is longer than a die or a matchstick.

This statement indicates that a particular leaf has a length of 4 centimetres. This measurement is comparable to the length of the matchstick mentioned earlier, suggesting that some leaves can be as long as a matchstick.

This statement provides the length of a wax colour stick as 7 centimetres. This measurement helps in comparing the size of a wax colour with other objects like a matchstick (4 cm) or a lizard (13 cm).

A standard scale found in a geometry box is typically used for measuring lengths. These scales are usually marked with numbers indicating centimetres. Most common geometry box scales are 15 centimetres long. Some may also be 30 centimetres long.

The little lines on a scale, which are usually smaller than the main centimetre marks, represent millimetres (mm). There are 10 millimetres in 1 centimetre. These smaller lines are used for measuring shorter lengths or for more precise measurements within a centimetre, allowing us to measure objects more accurately than just using whole centimetres.

To find objects that are about 10 cm long, you can look around your classroom or home. Examples of things that are approximately 10 cm in length include a standard pencil (unsharpened), a small screwdriver, a bar of soap, or a credit card. You can verify this by measuring them with a ruler.

Objects that typically measure between 10 cm and 20 cm in length include items like a spoon, a small water bottle, a mobile phone, a notebook, or an electric iron. You can use a measuring scale to check the lengths of these items and confirm if they fall within this range.

Items that are less than 1 cm long are very small. Examples include a single grain of rice, a small button, a tiny bead, or the head of a pin. Even smaller things like seeds of certain plants or small insects would also fit this description. Measuring these accurately might require a ruler with millimetre markings.

To determine which is longer, your thumb or your little finger, you can compare them visually or measure them. Generally, a thumb is longer than a little finger. You can measure both from their base to their tip using a ruler to find the exact difference in length.

To measure something using a rope, shoe string, or thread and find out the length in centimetres, you first need to use the rope, string, or thread as your measuring tool. Lay the rope straight along the object you want to measure, or use it to measure a distance. Once you have the length marked on the rope, you then compare that length against a standard measuring scale (like a ruler or measuring tape) that is marked in centimetres. You can then count how many centimetres the rope, string, or thread covers.

This exercise involves comparing personal measurements with those of a friend. The table shows sample measurements:

My measurement

• Nose: 3 centimetres
• Around the wrist: 12 centimetres
• Around the head: 36 centimetres
• Ear: 5 centimetres
• Hand (tip to middle finger to wrist): 12 centimetres

My friend's measurement

• Nose: 3 centimetres
• Around the wrist: 11 centimetres
• Around the head: 35 centimetres
• Ear: 5 centimetres
• Hand (tip to middle finger to wrist): 11 centimetres

By comparing these values, we can see that for the nose and ear, the measurements are the same. For the wrist, head, and hand, your friend's measurements are slightly less than yours. This highlights that even for similar body parts, there can be small differences in length.

To find the shortest road for Ant Gibli to reach the grains, we need to compare the lengths of the different paths shown. The shortest distance between two points is always a straight line. If 'Road B' is indicated as the shortest, it means that among the given options, the path labelled 'Road B' has the least length. Visually, it would appear as the most direct route from Gibli's starting point to the grains.

Yes, it is possible to draw a road shorter than the ones shown. The shortest possible road between two points is a straight line connecting them. If you draw a straight line directly from where Ant Gibli starts to the location of the grains, this line will be shorter than any curved or zig-zag path. To find the length of this shortest road, you would need to measure the straight line using a ruler marked in centimetres.

We need to decide whether to measure each item using centimetres (cm) or metres (m). Centimetres are used for shorter lengths, while metres are used for longer lengths.

• (i) Width of computer screen: Centimetres (Screens are relatively small.)
• (ii) Length of pagdi worn by Sikhs: Metres (A pagdi is a long piece of cloth.)
• (iii) Height of a one year old child: Centimetres (A one-year-old child's height is typically measured in cm.)
• (iv) Length of a banana: Centimetres (Bananas are short fruits.)
• (v) Waist of an elephant: Metres (An elephant's waist is very large.)
• (vi) Height of a sugarcane: Metres (Sugarcane stalks are tall.)
• (vii) Depth of a well: Metres (Wells are deep underground.)
• (viii) Height of your mother: Centimetres (While mothers can be tall, their height is usually measured in cm, though it could be converted to meters.)
• (ix) Distance from school to home: Metres (This is usually a significant distance.)
• (x) Length of your father's arm: Centimetres (Arm length is a shorter measurement.)

This section introduces a scenario about Marie and Baichung travelling to Agra. It mentions they arrive at Agra Cantt. Railway Station. This context is likely a setup for further questions related to distances, travel time, or measurements associated with their trip, which are not fully provided in the given text.