Tag Archives: free olympiad lessons

Grade 4 Maths (IMO) : Division

Let’s talk about what division really is — it is repeated subtraction; much the way multiplication is repeated addition.

Let’s say I have the basic problem 16 ÷  4.  I could start with 16 and then subtract 4, subtract another 4, another 4, and another 4 until I run out and reach zero.  I would have to do this 4 times. If I had 16 cookies that I wanted to share equally among 4 friends, I could do the “one for you, one for you, one for you, and one for you” process and still end up with 4 cookies for each.

But what about 375 ÷ 50? If I don’t know how to divide by double digit numbers, the repeated subtraction process might actually be a good choice . . . at least showing some number sense to know that 375 divided by 50 means “How many 50’s in 375?” I know if I subtract 50 six times, I still have 75 left. I can subtract another 50 and I have 25 left over. So 375 ÷ 50 = 7 with a remainder of 25.

Dividing using the distributive law

Division Possible Split Calculation Answer
69 ÷ 3 60 + 9 (60 ÷ 3) = 20(9 ÷ 3)  = 3 20 + 3 = 23
391 ÷ 3 390 + 1  (390 ÷ 3) = 130(1 ÷ 3) = cannot be divided 130 with Remainder 1

 Long Division

Before a child is ready to learn long division, he/she has to know: Continue reading →

Grade 3 Science (NSO) : Human body part 1

A look at the grade 2 lessons

Grade 2 Science (NSO): Human Body

Human beings: Parts of the body

Human beings : Sense organs

Our body is made up of different organs and organ systems. There are in all 12 systems in our body

Integumentary system 

The integumentary system consists of the skin, hair, nails, glands, and nerves. It’s main function is to act as a barrier to protect the body from  the outside world. It also functions to retain body fluids, protect against disease, eliminate waste products, and regulate body temperature.

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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.

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

A look at the grade 2 lesson

Grade 2 Science(NSO) : Food

Food can be divided into three types

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

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Grade 3 Science (NSO) : Birds

Bird, a warm-blooded vertebrate that lays eggs and has feathers and wings.

Type of beaks

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Grade 3 Science (NSO) : Air and water

Before starting lets take a look at the Grade 1 lessons

Air and Water : Properties

Air and Water : Use

Activities: Worksheets on Air and Water

Air

Living things need air to breathe

Moving air is called Wind

A gentle wind is called Breeze

A strong fast wind is called a Storm

A very strong wind is called Gale

Uses of moving air

A weather cock or wind vane is used to know the direction of the wind. At airports we use wind sock to know the direction of the wind. When aeroplanes fly in the direction of the wind , it saves fuel.

Wind makes windmill work. They are used to generate wind energy which is used to grind grains, pump water and make electricity.

Helps in sailing boats

A parachute falls slowly because of the wind

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Grade 2 Science (NSO) : Rocks and minerals

Rocks

Earth is made up of hard matter called rocks. They come in different shapes, colour and size. Rocks are found under the soil, in rivers and seas. They are solid material made up of one or more minerals.

Rocks can be hard ( granite) or soft (chalk)

Some important rocks :

Granite : 

Granite is a light-colored igneous rock with grains large enough to be visible with the unaided eye.

It is the most common igneous rock found on the Earth’s surface

Granite is composed mainly of  quartz and fedspar  with minor amounts of mica and other minerals. This mineral composition usually gives granite a red, pink, gray, or white color with dark mineral grains visible throughout the rock .

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Grade 3 Science(NSO) : Leaf

Functions of a leaf

Absorbs sunlight

Help in exchange of gases

Carries out photosynthesis

Apex : Tip of leaf

Base : Attaches to petiole ; if petiole is absent attaches directly to stem

Margin : Edge of leaf

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Grade 2 Science (NSO) : Good habits and safety rules

Before starting lets take a look at the Grade 1 lessons

Human beings: Good habits

Safety: Safety rules

Safety: Traffic rules

Safety: Activities and worksheets

Safety Rules

Safety rules at home :

  • Do not play with match sticks, scissors, switches, plugs , fire, knives etc
  • Keep things in proper places afetr using them
  • Immediately inform an adult if you get hurt

Safety rules on the road

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Grade 3 Science(NSO):Plants : Stem

Stem

Stems are the aboveground structures that bear the plant’s leaves and flowers. The stem provides a host of services to the plant:

  • It provides a pathway for transporting water up to the leaves, and moving the sugars produced in the leaves down to nourish the roots.
  • It acts as a sturdy mast to hold up the leaves and help orient them for maximum exposure to sunlight.
  • It can act as a storage site for carbohydrates.

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