Meet Ndakson. He is 10 years old and in Grade 5 at the village school. Ndakson always comes top of his class. "What's his secret?" his schoolmates ask themselves.

"He's excellent in reading and writing. How does he do it?" they wonder. Ndakson tells them it is because he reads lots of books. While they waste their time doing nothing, he spends all his free time reading.

Ndakson sometimes earns #200 a week in pocket money. He spends most of the pocket money on books at the second-hand book shop in his village.

So how does Ndakson earn enough pocket money for these books? Read on to find out.

Meet Pedro, the family's milking cow. She produces over 20 litres of milk per day. Ndakson's father sells the milk.

A cow needs food and water, and time to graze in the veld. So each day after school Ndakson helps with this work. Ndakson's father gives him pocket money for the work he does. And it is this money that Ndakson saves to buy books each week.

First, Ndakson gives Pedro a bunch of carrots. He gives her exactly eight carrots a day. Each day he picks the carrots from his father's vegetable patch, enough for a day at a time.

You can work it out. You will find that Pedro eats nearly 60 carrots a week. Can you tell exactly how many?

After that, Ndakson takes Pedro to graze in the fields. His father warned him to watch the time and not give Pedro more than three quarters of an hour to graze.

Pedro usually starts grazing at about quarter past two, so that Ndakson can take her back to the milking shed at 3 o'clock. In winter when it gets dark earlier, Ndakson may start grazing earlier, around half past one.

Next Ndakson gives Pedro water. Without water Pedro won't produce milk, no matter how much Ndakson feeds her. Ndakson fetches buckets of water from the village pump because there isn't one nearby.

Pedro's trough holds about 30 litres of water. Ndakson's bucket only holds 5 litres. So to fill the trough Ndakson has to make many trips. Can you work out how many trips he has to make?

Then, Ndakson takes Pedro to his father to get her daily 12 kg bag of grain. Ndakson calculates that's almost 90 kg a week.

Each bag costs #39. Ndakson works out the cost of grain for each week. First he works out the cost of 7 bags at #40, which makes #280. Then he subtracts #7 to get #273. "That's over #1 000 a month!" Ndakson estimates. Is he correct?

Ndakson's father milks Pedro twice a day. She produces about 24 litres of milk a day, so about 12 litres for each milking.

Sometimes Ndakson helps with the milking but it is not as easy as it looks. "One day," he thinks to himself, "I will have my own cows and I will have to do all the milking myself."

His father pours the milk from the big bucket into smaller two litre cans or one litre bottles. He then sells the milk for #8 a litre.

Once a week Ndakson's father donates 25 litres of milk to the school feeding scheme. Each child gets a quarter litre of this milk. That means that 100 children get milk on this day.

For each litre of milk sold, his father gives Ndakson 50k. That doesn't sound like a lot, but if his father sells 24 litres a day, it adds up to quite a bit. Can you tell how much?

Ndakson saves his money until Saturday when he makes a trip to the book shop. Each book costs less than #10, so in a good week, he can buy quite a few.

Ndakson also loves to drink Pedro's milk. His father says that milk helps to build strong bones and teeth and makes a person fit and healthy.

So by drinking milk and eating lots of vegetables from his father's garden, Ndakson is strong and healthy. He seldom gets sick and never goes hungry.

Ndakson never forgets to thank Pedro at the end of each day. He rewards her with extra carrots or spinach leaves that he finds lying around the garden.

"Thank you Pedro, you are my best friend! It is thanks to you that I am strong, healthy and clever. If not for you I would never be able to buy all the books that help me be top of my class."