Calculating the number of bananas needed to feed a school

By MUNGAI KIHANYA

The Sunday Nation

Nairobi,

01 June 2025

Daniel Gitahi is the principal at a school with 1,500 children. He says that they have plenty of good fertile land and he has been thinking about using it for the benefit of the children. He wants to grow bananas and wants to know how many plants he needs to give each child one fruit daily.

The starting point for the calculation is the number bananas required daily: this is just the number of children, that is 1,500. Now bananas are grouped in hands and bunches; one hand can have about 10 to 15 fruits and one bunch has about 10 to 15 hands. All in all, one bunch generally has between 150 to 200 fruits (fingers).

So, to supply 1,500 fruits, the school will need at least 10 bunches of 150 fingers each daily. Bananas mature in about 9 to 12 months and, after that, they produce fruit every 8 to 9 months.

Working with the higher figure of 9 months (or 270 days), we find that the school that needs a constant supply of 10 bunches daily will require to grow a total of 2,700 banana plants. How much land is needed for this?

Bananas are normally grown with a spacing of about 2.5m by 2.25m. Thus, each plat needs about 6.25 square metres (2.5 x 2.5) of free space. So, 2,700 plants will need about 16,875sq.m – which we round off to 17,000sq.m – of land. This is equivalent to 1.7 hectares or slightly more than 4 acres.

To be on the safe side, I advised Daniel to grow the bananas on five acres, but he said that it sounds like a commercial plantation – “5 acres of bananas, are you serious? I will have to employ very many people to tend the plants and harvest them”, he said.

Well, one banana daily is a bit on the high side, but perhaps Daniel can consider one weekly. In that case, we just divide the above numbers by seven to get: 385 plants grown on about 0.6 of an acre. He said he would try this out and see how it goes – “half an acre is manageable”.

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Victor Mugo asks: “How come we see the same stars, when the Earth goes round the sun in a year, [why] can’t we see different stars on the other side?” This is not true. We see different stars in different months. That’s why the ancient civilisations came up with constellations - Aries, Taurus, Gemini, Cancer, etc.