Time and Calendar
Hours, Minutes and Seconds
Hour, minute and second are the unit for the measurement of time
24 hours = 1 day;
1 hour= 60 minutes;
1 minute = 60 seconds;
Hence, 1 hour\[=60\times 60=3600\,\sec onds\].
Example:
Convert 5 hours in seconds.
(a) 18000 seconds (b) 19000 seconds
(c) 21000 seconds (d) All the above
Answer (a)
Explanation: \[1\,hour=60\times 60=3600\,\sec onds\].
So\[5\,hour=5\times 3600\,\sec onds=18000\,Seconds\]
Clocks
Clocks are the devices that let us know of the times in a day. See the examples given below:
The small hand in a clock is for hour and the big hand is for the measurement of minute.
Example:
Hour hand of a clock is at 3 and minute hand is at 4 then the time will be:
(a) 3 : 20 (b) 3 : 50
(c) 3 : 10 (d) All the above
(e) None of these
Answer (a)
Example:
In how many rotation of hour hand of a clock complete 12 hours?
(a) 2 (b) 1
(c) 60 (d) All the above
(e) None of these
Answer (b)
Explanation: Hour hand of a clock complete one rotation in 12 hours.
Digital Clocks
The clocks that shows the time in numbers are called digital clocks. Given below are the examples of digital clocks.
Example:
A man walks 2 hours 20 minutes in the morning and 1 hour 30 minutes in the afternoon. Find the total hours he walks in a day.
(a) 3 hours 50 minutes (b) 3 hours 40 minutes
(c) 2 hours 20 minutes (d) All the above
(e) None of these
Answer (a)
Explanation: 2 hour 20 minutes + 1 hour 30 minutes = 3 hours 50 minutes.
Calendar
Calendar is the systematic arrangement of dates and months of the year. There are 12 months in a year.
The following are the name of the months and their number of days:
Geometrical Figures
Line
Let's see the lines given below:
Example:
Give the name of all slant lines from the figure given below.
(a) AD and BC (B) AB and BC
(c) AB and AD (D) All the above
(e) None of these
Answer (a)
Example:
Which one of the following is correct about the line?
(a) A straight line is measured by ruler.
(b) A straight line cannot be measured by ruler.
(c) A straight line is measured in grams.
(d) All the above
(e) None of these
Answer (a).
Note: We use ruler to measure a straight line.
Angle
An angle is formed at the meeting point of two lines or an angle is formed when two lines meet. The point where two lines meet is called vertex. See the figures given below:
Example:
Which one of the following is correct about the angle?
(a) Both sides of an angle must be equal in length
(b) Both sides of an angle may be unequal in length
(c) Two lines cannot form an angle
(d) Three lines are required for formation of an angle
(e) None of these
Answer (b)
Example:
Which one of the following is representing an angle?
Answer (c)
Note: Both the sides of an angle may be unequal in length.
Square
A square has four equal sides and four equal angles.
In this picture side AB = BD = CD = AC
And \[\angle A=\angle B=\angle C=\angle D=90{}^\circ \]
Example:
If the sum of three angles of a square is\[270{}^\circ \], then the measurement of its fourth angle will be?
(a) \[70{}^\circ \] (b) \[80{}^\circ \]
(c) \[90{}^\circ \] (d) All the above
(e) None of these
Answer (c)
Explanation: Each angle of the square is\[90{}^\circ \].
Quadrilateral
Properties
A quadrilateral has:
4 sides (edges)
4 vertices (corner)
The following are the quadrilaterals:
Example:
A plane figure has four sides and four vertices. The name of the plane figure is:
(a) Quadrilateral (b) Triangle
(c) Pentagon (d) All the above
(e) None of these
Answer (a)
Rectangle
Properties
In a rectangle:
Opposite sides are equal.
Opposite sides are parallel.
All angles are equal.
See the figure given below:
Here,
AB = CD
And AC = BD
\[\angle A=\angle more...
Measurement
Measurement of Length
There are various units for the measurement of the length. These are metre, centimetres, kilometres etc. The standard unit for the measurement of the length is metre.
1 centimetre = 10 millimetres
1 metre = 100 centimetres
1 kilometre = 1000 metres
Example:
A rope is 45 centimetres long. What will be the length of the rope in millimetres?
(a) 450 millimetres (b) 4500 millimetres
(c) 405 millimetres (d) All the above
(e) None of these
Answer (a)
Explanation: 1cm = 10 millimetres, 45cm = 450 millimetres
Conversion between Metre and Centimetre
1 metre \[=1\times 100=100\]centimetres
2 metres \[=2\times 100=200\]centimetres
100metres \[=100\times 100=10000\]centimetres
Example:
Convert 450 metres into centimetres
(a) 45000 cm (b) 4500cm
(c) 2550 cm (d) All the above
(e) None of these
Answer (a)
Explanation: 1 m = 100 cm.
Conversion between Kilometre and Metre
1 Kilometre \[=1\times 1000=1000\,\,metres\]
2 Kilometre \[=2\times 1000=2000\,\,metres\]
100 Kilometres \[=100\times 1000=100000\,\,metres\]
Example:
Convert 9 km 500 m in metres.
(a) 8400 metres (b) 9500 metres
(c) 7900 metres (d) All the above
(e) None of these
Answer (b)
Explanation: 9 km 500 m \[=(9\times 1000+500)\]
Measurement of Masses
Mass is measured in grams and kilograms. Small masses are measured in milligrams.
1 gram \[=1\times 1000=1000\] milligrams
1000 grams = 1 kilogram
Example:
John bought the following items from the market: 3 kg 500 grams of potatoes, 4 kg 200 grams of onions and 2 kg 700 grams of green vegetables. What is the total weight of the items?
(a) 10 kg 400 grams (b) 6 kg 300 grams
(c) 7 kg 100 grams (d) All the above
(e) None of these
Answer (a)
Explanation: Total weight = 3 kg 500 grams + 4 kg 200 grams + 2 kg 700 grams = 9 kg 1400 grams = 10 kg 400 grams.
Measurement of Volume
The standard unit for the measurement of volume is litre. Volume of a liquid is measured in millilitres, litres and kilolitres.
1 litre \[=1\times 1000=1000\] millilitres
2 litres \[=2\times 1000=2000\] millilitres
1000 litres = 1 kilolitres
Example:
To obtain the volume of oil in litres how much quantity of oil is required in a container, which already contains 45 litres 900 millilitres of oil?
(a) 500ml (b) 100ml
(c) 600ml (d) All the above
(e) None of these
Answer (b)
Explanation: 45 litres 900 millilitres of oil becomes 46 litres when 100 millilitres is added to it.
We live in our house with our family members. A society is formed in this way. Nearby living people becomes our neighbor. Neighbors help each other.
Neighbors celebrate festivals and other rituals together.
There are many services which are available in the neighborhood such as post office, bank, police station, fire station, hospital, market, railway station, school etc.
There are many people who help us in different kind of works - chemist, green grocers, and black smiths, carpenter, tailor, Cobbler, plumber, electrician etc.
Post office is the place where we post letter. We drop letters in the letter box. They are located in every town, village and city. We send things through parcel.
Bank\[\to \] It is an institution/ place where are we deposit money and can take them out when required. Bank take care of our money. We can make use of ATM to window money. ATM is an automatic machine that allows people to take out money any time.
Police station\[\to \]There are police stations in every town to maintain the law and order of a place/country.
Fire station\[\to \] a fire station is a structure where firefighting apparatus are kept for any kind of emergency.
Hospital\[\to \]A hospital is a place where the sick and the injured are taken for treatment. Doctor, nurses and other staff help us in treatment we are sick
Market\[\to \] A market is very busy place where people go to buy the articles of their need. There are many shops in a market.
Railway station\[\to \] Railway station us a place where trains come and go to different places. Railway is a place where trains stop. Some stations are small and some are big. It is a busy place. We book our tickets before boarding the train. Trains are the fastest and cheapest means of communication which are used to go distant places.
School\[\to \] The most important part of one’s life is spent at school. We learn to write, read, sing, dance, respect, obey and love teachers. School is training ground for all virtues that makes a good citizens. more...
Plants are one of the oldest living organisms on the earth.
Plants are living organisms which need air, water and sunlight to survive.
Plants provide food to other living organisms.
Plants play a very vital role as they provide oxygen for living organisms on earth for their survival.
Plants gives us many things such as wood, medicines, paper, furniture etc.
Plants helps in keeping environment fresh and cool.
Plants are mainly of two types - terrestrial and aquatic.
Plants which grow on the land are called terrestrial plants, e.g. papaya tree, mango tree, neem tree etc.
Plants which grow in water are called aquatic plants, e.g. Water lily, lotus, bonsai etc.
On the basis of structure, plants are divided into mosses plants, grasses, dicots and monocots.
Dicots and monocots include big plants shrubs or bushes, climber, creepers etc.
Big plants are tall, voluminous trees e.g. mango tree, banyan tree, oak tree, neem tree etc.
Herbs are mainly used for flavor and scent and have medicinal value. They are used for cooking purpose, e.g. basil, tulsi leaves, spinach mint, coriander leaves.
Shrubs or bushes are smaller woody plants and have and short stem. e.g. rose plant, cotton etc.
Creepers plants grows along the soil surface and has weak stem and spread on a long distance. They can be flowering or non- flowering, e.g. pumpkin, bottle gourd etc.
Climber plants have very soft and weak stem. They grow only with the help of support.
They can be both flowering and non-flowering, e.g. beans plant, jasmine plant etc.
Mainly, a plant has roots, stem, leaves, flower, fruits and seeds, e.g. picture of parts of a plant.
We get food from different parts of plants. We get cereals, pulses, wheat, fruits and vegetables, spices, sugar, tea, coffee, mustard oil, sunflower oil, coconut oil from plants.
Different parts of a plant and their function are as follows.
Animals move from one place to another in search of food, shelter and to themselves from the enemy.
Plants and animals both are living organisms. Animals depends upon plants for food animals are known as consumers and plants are called producer in a food chain.
Animals that can be tamed and kept at homes and farms are called domestic anima cow, goats, buffalo’s horse etc.
Uses: donkey is used for load carrying, oxen for cultivation, cow gives us milk etc.
The skin of some animals like snakes, crocodiles, camels etc. are used as leather.
Some animals like cats, dogs, rabbits and birds are kept at home are known animals.
Animals which live in forests are called wild animals. These animals are danger lion, tiger, wolf, fox, deer, giraffe, monkey etc.
Herbivores animals eat only plants, fruits and vegetables, e.g. cow, deer, goat, etc.
Carnivore’s animals eat only flesh of other animals e.g. Lion, tiger, leopard, eagle, snake, fox etc.
Omnivores animals eat both plants and animals e.g. crow, human beings, rat beer etc.
Scavengers are wild animals which eat the remains of dead animals e.g. vulture, fox and jackal etc.
Homes of some animals- cow-cowshed, dog-kennel, horse-stable, lion and tiger-den, rabbits, rats and snake-holes, monkey and birds-trees.
Environment includes everything, i.e. vegetation, water, microorganisms, soil, rocks, atmosphere, etc.
Our environment consists of both living and non-living things.eg. Atmosphere, sea, river, lakes, soil etc.
Atmosphere means the sphere of air surrounding the earth. Mainly, there are four sub- systems called spheres, they are land (lithosphere), water (hydrosphere), living things (biosphere) and air (atmosphere).
The atmosphere consists of four unique layers:
The troposphere (0-8 miles)
The stratosphere (8-30 miles)
The mesosphere (30-50 miles)
The thermosphere (50-120 miles)
Atmosphere protects the life on the earth. Atmosphere has gases like nitrogen hydrogen, carbon dioxide, argon, helium and some more gases. It has 78% nitrogen, 21% oxygen and 1% other gases.
Oxygen is the most important gas of atmosphere, as most of the living organisms inhale it.
Seas are the natural source of water.
Rivers are natural source of water. It is usually freshwater, flowing towards an etc. e.g. Ganges, Yamuna.
Lakes are both natural and man-made. A lake is a still water body surrounded by from all sides. Lakes are a body of fresh or salt water of considerable size surrounded by land. E.g. Dal Lake, Wular Lake Etc.
Soil is a natural resource made up of tiny particles of broken rock, mineral, clay and humus. Soil is an important ingredient for the survival of living organisms on earth.
There are mainly three types of soil-sandy soil, clayey soil and loamy soil.
Hard surface of the earth consists of rocks. The earth is made up of hard matter called rocks. They are many shapes, Sizes and colour.
Various kinds of rocks are
(i) Granite \[\to \]It is used for making buildings and statutes
(ii) Marble \[\to \] It is used for making building and statutes
(iii) Sandstone\[\to \] These rocks are soft in nature.
Coal, slate, graphite, chalk is also soft.
Air is present in the environment. Air is a mixture of different gases like nitrogen, oxygen, carbon dioxide etc.
Air contains 78% nitrogen, 21% oxygen and remaining 1% other gases.
Living things need air to breathe. We must breathe in fresh and clean air.
Wind is the movement of air, there are mainly two types of wind - global wind and local wind.
Global winds are the dominant prevailing wind patterns that blow in a fairly, constant, steady direction across our earth.
Local winds are small scale wind of local origin caused by temperature difference. They can move up, down and horizontal. E.g. wind of mountain areas.
Breeze \[\to \] A gentle wind is called breeze. Motion of air from sea to land is called sea breeze and land to sea is called land breeze.
Storm \[\to \] A storm is very bad weather, with heavy rain, strong winds. It includes thunder and lightning. So, storm is a strong wind, it can be dust storm, snow storm, rainstorm etc. e.g. of circular storm is cyclone. It causes damages to trees, houses and other things.
A very strong wind is called gale.
All living things need water to live. Life is impossible without water.
Water, ice and water vapors are three states of water. All the three forms are inter convertible.
Freezing point of water is \[0{}^\circ C\]and boiling point of water is\[100{}^\circ C\].
We get water from rain. These are the sources of surface water. The main sources of' water are rivers, lakes, ponds and reservoirs.
Some rainwater seeps into the ground called ground water.
Water cycle \[\to \] As the Sun heats up the water in river, lakes, ponds and sea, the water vapor rises. Then, it cools and forms small water droplets. Cloud are formed which give rain, which goes back to seas and rivers. This is called water cycle.
Evaporation \[\to \] the change of state from a liquid to a gas is called evaporation.
Rate of evaporation depends upon temperature, wind, area of exposed surface and humidity.
Condensation \[\to \] the change of state of steam from a gas to a liquid is called condensation.
Water is very precious. So we should conserve it. Reducing, revising and recycling are the ways of conserving water.
There are mainly four seasons in a year - summer, winter, autumn and spring.
Weather of a place is the combined effect of Sun, air, water and clouds.
The small hand in a clock is for hour and the big hand is for the measurement of minute.
Example:
Hour hand of a clock is at 3 and minute hand is at 4 then the time will be:
(a) 3 : 20 (b) 3 : 50
(c) 3 : 10 (d) All the above
(e) None of these
Answer (a)
(a) AD and BC (B) AB and BC
(c) AB and AD (D) All the above
(e) None of these
Answer (a)
Answer (c)
Note: Both the sides of an angle may be unequal in length.
Square
A square has four equal sides and four equal angles.
In this picture side AB = BD = CD = AC
And \[\angle A=\angle B=\angle C=\angle D=90{}^\circ \]
Here,
AB = CD
And AC = BD
\[\angle A=\angle more... 
FUNDAMENTAL
School\[\to \] The most important part of one’s life is spent at school. We learn to write, read, sing, dance, respect, obey and love teachers. School is training ground for all virtues that makes a good citizens. more... 
FUNDAMENTALS
FUNDAMENTAL
