# Vedic Maths: Base and Complement

Base and Complement are very important in Vedic Mathematics and form the basis of many calculations.

## Base:

As explained above we work in a base 10 number system. In order to ease our calculations we can take any number ending with ‘0’ i.e. any multiple of 10 as our base.

## COMPLEMENT

The Complement of a number is the difference between that number and the next higher power of 10.

### 10’s complement:

This includes all 1 digit numbers. It is the number that should be added to make it 10.

The complement of 6 is 4.
The complement of 7 is 3.

### 100’s complement:

This includes all 2 digit numbers. It is the number that should be added to make it 100.

The complement of 55 is 45.
The complement of 89 is 11.

# NSO for Class 3 : Syllabus

## Grade 3 Syllabus for NSO

### Plants and Animals

Different parts of a plant and their functions

Animals

# Grade 3 Science (NSO) : Earth and Universe

A look at the previous lessons on earth and universe :

Grade 2 Science (NSO) : Earth and universe

Weather and The Sky: Earth and Sky fundamentals

## Earth’s Revolution

The motion around the sun along its orbit is called a revolution . The amount of time it takes for a single trip around the sun is called a period of revolution. The period for the Earth to revolve around the sun is 365.24 days or one year. The .24 days is why every four years February has 29 days.

There are 4 seasons in an year .In Autumn and Spring the northern and southern hemispheres are tilted equally toward the sun.In Summer the Earth is on the other side of the sun and the northern hemisphere is tilted  toward the sun and gets better sun rays. In winter the northern hemisphere is tilted away from the sun. That’s how we get seasons.

Earth’s orbit around the sun is slightly elliptical, Earth is actually slightly closer to the sun in the winter than it is in the summer.It is the tilt of Earth’s axis that causes the seasons.

# Grade 3 science (NSO) : Human body part 3

Links to part 1 and part 2 of the human body

Grade 3 Science (NSO) : Human body part 1

Grade 3 Science(NSO) : Human body part 2

## Nervous system

This system controls all our actions, sense of feelings and thinking is called Nervous system.The nervous system is a complex collection of nerves and specialized cells known as neurons that transmit signals between different parts of the body. It is essentially the body’s electrical wiring.

• It consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body
• Brain is the most vital organ of our body
• It sends and receives messages to and from all parts of the body through nerves
• Spinal chord is the bundle of nerves that runs up and down the center of the back; connects the brain to the nerves; carries signals between the brain and other parts of the body
• The brain and spinal cord form the control center known as the central nervous system (CNS).

# Grade 3 Science(NSO) : Human body part 2

We have already covered Skeletal, immune, cardiovascular, muscular and integumentary system in part 1.

Grade 3 Science (NSO) : Human body part 1

## Lymphatic system :

It is responsible for the removal of interstitial fluid from tissues. It absorbs and transports fatty acids and fats as chyle from the digestive system. It transports white blood cells to and from the lymph nodes into the bones.

# Grade 3 Science (NSO) : Food part 3 – Preservation of food

## Food Decay and Preservation

Bacteria and fungi are the main groups of  decomposer organisms. Food decay is also known as food spoilage.

Bacteria and fungi need Food , Warmth and Moisture to grow.

There are several ways to stop or slow down the decay of foods. This is known as Food Preservation.

## Food preservation methods

### Freezing

Bacteria cannot reproduce at low temperatures.

Bacteria and fungi need warmth to grow. In low temperatures they stop growing.

Following is the list of food preserved by freezing;

• Meat
• Fish
• Fruits
• Vegetables
• Fresh foods
• Cooked foods

### Drying

Removing water prevents the microorganisms from growing, or digesting the food.

# Grade 3 Science (NSO) : Food Part 1 – Food Types

A look at the grade 2 lesson

## Energy giving food

Give us energy to work. They contain carbohydrate and fats.

### Carbohydrates

They are found in foods like rice, pasta, cassava, yam etc. when starchy foods are eaten and digested, simple sugars like glucose are obtained. It is this glucose that the body uses for energy.

There are two major types of carbohydrates:

1. Simple carbohydrates (Sugar)

• Fruits
• Milk
• White sugar you would find in a sugar bowl
• Chocolates

# Grade 3 Science (NSO) : Food Part 2 – Methods of Cooking

### Cooking of food

Cooking improves the flavor of food and also makes the food easier to chew and more digestible. Micro oirganisms present in the food are killed during cooking which makes the food safer to consume. Various methods of cooking are listed below :

### Boiling

Involves cooking the food at the boiling temperature of water ie 100 degree centigrade.

Example : Eggs , potatoes etc