Table of Contents
1. The Fish Tale
Deep under the sea
See the lovely coloured fish Swimming peacefully
This special poem in three lines is called a Haiku. Such poems about nature are popular in Japan. Here is another Haiku—
The lake, calm, smooth, still A fish jumps up and returns Ripples shake the lake
Do you know any poems about fish?
Here are some drawings made by children.
When you think of fishes what shapes come to your mind?
* Try to use a square and a triangle to draw a fish.
Look for fish designs around you — on cloth, in paintings, on mats, etc.
‘Meen’ means a fish and Meenakshi is a girl whose eyes look like a fish. Can you think of someone who has such eyes?
* Draw a face with ‘fish eyes’.
Fishes can have very different sizes. The smallest fish is about 1 cm long. How long is the biggest fish you can imagine?
* How many times longer is your big fish than the smallest fish?
The biggest fish is the whale shark. It is actually not a whale but is a big, big fish. Whales are different from fish. Whales breathe like we do, through their noses. But fish have no noses and they take in water, not air. Whales give birth to babies, but fish lay eggs. The whale shark fish looks big and dangerous, but is quite harmless. It does not attack humans.
One whale shark was as long as 18 m. Just think how long that is – almost 12 children of your size standing one on top of the other! And guess what it weighed? Well, much, much more than what 12 of you together weigh! Its weight was about 16000 kg!
* About how many kilograms do you weigh? _____
* So12 children like you pu ttogether will weigh about_____ kg.
* About how much more does the whale shark weigh than 12 children like you put together? _____
The Fish Tail
To see the difference between whales and fish look carefully at their tails. Can you see that the fish tail stands flat along its body, but the tail of the whale almost looks like two legs. Can you spot the fish in the picture?
“Schools” of Fish!
Fish like to swim together in the sea in big groups called “schools” of fish. In their school they feel safe from the bigger fish. (Do you feel safe in your school?)
This is a thematic chapter which presents to children the world of fish and fish workers through an integrated approach. Mathematical concepts, such as shapes, estimation, sense of large numbers, simple operations, speed, loans, etc. are woven into reallife contexts to allow a creative revision of some ideas learnt earlier.
To scare away the bigger fish, some small fish drink up a lot of water, swell up and look big!
* Jincy used these shapes to make drawings of fish. Now you also use some shapes to draw the different sea animals shown below.
* Which of these sea animals have you seen before?
Fishermen in their Boats
Which of these sea animals have you seen before? How many of you have seen the sea? Where did you see it? Did you see it in a movie or for real? How deep do you think the sea could be? Find out.
Do you know how to swim? Would you be scared of the high sea waves?
* Close your eyes and imagine the sea with waves rising high.
* How high do you think the waves can go? _____
Imagine that there are fishermen in their boats, going up and down with the waves.
They start their trip when it is still dark.
Some go on a simple boat made from logs of wood tied together. If the sea is rough, with very high tides and a strong wind, then these fishermen have a very difficult time.
These log boats do not go very far.
If the wind is helpful, they travel about 4 km in one hour.
* How long will they take to go a distance of 10 km?
* Guess how far you can go in one hour if you walk fast.
Fishermen can feel the wind and look at the sun to find out which way to go. Many of us would get lost and not be able to find our way on the sea where you only see water, water, and nothing else!
Look at the sun and find out the direction from where it rises.
Find out
* From where you are, what interesting thing do you see to your east?
* Name two things that are lying to your west.
What a Catch!
Out on the sea, fishermen look for a place where they hope to find a good catch of fish. There they spread their nets. They will have to wait for many hours for the fish to come into their nets.
* Look at the different types of boats.
Some boats have motors and go further into the sea. Since they go far out they can catch more fish. These boats travel faster, at the speed of about 20 km in one hour.
* How far would the motor boats go in three and a half hours?
* How much time will they take to go 85 km?
But the fishermen are now very worried.
There are some very big machine boats (trawlers) in the business. They go far out and put their big nets deep in the sea. This way they collect a whole lot of fish, leaving very few near the sea shore. They also stay out on the sea for many days.
These big machine boats also catch the small baby fish, which have yet to grow up. Fishermen in the smaller boats always let the baby fish pass through their nets to go back into the sea. They choose a net size in such a way that only the grown up fish are caught.
For hundreds of years fishermen have cared for the sea and its fishes, and fished only a little to eat and sell.
They say that if trawlers catch thousands of kilograms of fish everyday, there will be no fish left in the sea!
* Write a news report about the dangers faced by the fishes in our rivers and seas.
Which Boat Gets How Much?
In one trip the log boat brings about 20 kg of fish. But other types of boats bring a bigger catch as given in the table. The table also shows the speed of each type of boat, which is how far each boat goes in one hour. Look at the table and calculate 
a) About how much fish in all will each type of boat bring in seven trips?
b) About how far can a motor boat go in six hours?
c) If a long tail boat has to travel 60 km how long will it take?
Type of boat  Catch of fish in one trip (in kg)  Speed of the boat (how far it goes in one hour) 
Log boat  20  4 km per hour 
Long tail boat  600  12 km per hour 
Motor boat  800  20 km per hour 
Machine boat  6000  22 km per hour 
Some Big, Big Numbers!
In the Class IV MathMagic you heard of the number ‘lakh’ which is equal to a hundred thousand. You had read that there are about one lakh brick kilns in our country, where bricks are made.
* What other things have you heard of in lakhs?
* Write the number one thousand. Now write one hundred thousand. So how many zeroes are there in the number one lakh? Easy, isn ’t it?
* There are about two lakh boats in our country. Half of them are without a motor. What is the number of boats with a motor? Write it.
* About one fourth of the boats with a motor are big machine boats. How many thousand machine boats are there? Come on, try to do it without writing down.
We might wonder about the number of people whose lives are related to fish. In all there are about one hundred lakh fish workers — who catch fish, clean and sell them, make and repair nets and boats, etc. We also have a name for this big number – ‘one hundred lakh’ is called a crore.
* Where have you heard of a crore? What was the number used for?
* Try writing the number one crore. Don't get lost in all the zeroes!
The Fish Market
Have you been to a fish market? If you have then you might know why a very noisy place is sometimes called a fish market !
This fish market is busy today.
Many boats have brought a good catch. The fisherwomen are shouting out their prices to the buyers.
Mini — “Come here! Come here! Take sardines at Rs 40 a kg”.
Gracy — “Never so cheap! Get swordfish for Rs 60 a kg”.
Floramma sells prawns for Rs 150 a kg.
Karuthamma sells squid for Rs 50 a kg.
Look, Fazila can hardly carry this big kingfish! She says, “This fish weighs 8 kg. I will sell the whole for Rs 1200”.
Practice Time
1) At what price per kg did Fazila sell the kingfish?
2) Floramma has sold 10 kg prawns today. How much money did she get for that?
3) Gracy sold 6 kg sword fish. Mini has earned as much money as Gracy. How many kg of sardines did Mini sell?
4) Basheer has Rs 100. He spends onefourth of the money on squid and another threefourth on prawns.
a. How many kilograms of squid did he buy?
b. How many kilograms of prawns did he buy?
Try saying this fast!
Here is a tongue twister. Repeat it fast!
She sells sea shells on the seashore.
She is sure that the shells that she sells will be there no more.
Women’s ‘Meenkar Bank’
The meeting of the Meenkar Bank has just begun. Fazila is the president. Twenty fisherwomen have made their own bank. Each saves Rs 25 every month and puts it in the bank.
* How much money does the group collect each month?
* How much money will be collected in ten years?
Practice time
Gracy needs money to buy a net. Jhansi and her sister want to buy a log boat. So they take a loan from their bank. They will return it with interest.
a) Gracy took a loan of Rs 4000 to buy a net. She paid back Rs 345 every month for one year. How much money did she pay back to the Bank?
b) Jhansi and her sister took a loan of Rs 21,000 to buy a log boat. They paid back a total of Rs 23,520 in one year. How much did they pay back every month?
Earlier women did not go on the boat to fish. But now Jhansi and some others are going on the boats during the day. Things are changing now and their Bank helps them. They have also got a special bus to take their baskets full of fish.
Why Don’t We Start a New Fishdrying Factory?
The women of Meenkar Bank also want to start a factory to dry fish. The Panchayat has given them some land for that. Over the years they have saved Rs 74,000. They find out how much they will need for the factory.
Fazila writes the things they need to buy to begin. See the table for the cost of each item and the number of items they want to buy. Find the total cost.
Item  Price of each  Number of items  Cost 
Bore well for fresh water  Rs 3000  1 

Bamboo rack for fish drying  Rs 2000  20 

Cement tank  Rs 1000  4 

Tray and knife  Rs 300  20 

Bucket  Rs 75  20 

Total cost to set up the factory = _____
When fresh fish is dried it becomes 1/3 its weight.
In one month they plan to dry 6000 kg of fresh fish.
How much dried fish will they get in a month? _____
Floramma — Let us first calculate for 6 kg of fresh fish.
We buy fresh fish for  Rs 15 per kg 
We sell dried fish for  Rs 70 per kg 
We dry 6 kg fresh fish to get _____kg dried fish
For 6 kg fresh fish we have to pay 6 × __ = Rs 90
We will sell 2 kg dried fish and get 2 × __ = Rs __
So if we dry 6 kg fresh fish we will earn __ – 90 = Rs __
But if we dry 6000 kg we can earn Rs __ × 1000 in one month!
They are all very happy with this plan. The group can make profits and each
woman can get a salary for the work she does.
Jhansi — I found that for 6000 kg fish we would need 1500 kg salt every month! Its price is Rs 2 per kg.
Monthly costs:
a) Salt 1500 × 2 = Rs ____
b) Packing and bus charges = Rs 3000
So the total monthly cost of drying and selling the fish = Rs _____
Fazila — That sounds very good! Our calculations tell us that every month our Bank will earn Rs 44,000!
* Check to see if you also get the same answer.
Find out
Songs sung by fishermen are beautiful. Find out about the words and tunes of such songs.