We all live with computers鈥ut getting the most out of them鈥 getting them to do what you need鈥an be kind of difficult.
But if you can understand how they process things, a computer can be the most useful housemate you鈥檒l ever have.
Computers are good at carrying out tasks right? The answer is yes, as long as you spell out clearly what you want them to do.
One key to 鈥淐omputational thinking鈥 is turning complicated tasks into smaller tasks鈥y pulling them apart.
It鈥檚 called decomposition.
Ada:
What鈥檚 that smell?
Voice over:
Decomposition might sound like something that happens to old food.
Ada:
Yuck!
Voice over:
But it鈥檚 also the process of breaking down a problem into smaller, simpler parts to make it easier to solve.
Ada:
It鈥檚 time to do some shopping.
Voice over:
Take a simple everyday task like shopping. How would you ask a computer to do it?
Ada:
Will you please go shopping for a change鈥 Agggh!
Voice over:
Shouting at computers just doesn鈥檛 work. You have to ask in the right way. You know what I mean by 鈥淕o Shopping鈥 but computers don鈥檛. They don鈥檛 work in English they work in 鈥楥omputer Language鈥 and only understand simple instructions. So you need to break the task down into simpler parts that they do understand, by decomposing the problem鈥 Step by step.
When you think about it - doing the shopping is actually lots of tasks done one after another 鈥 starting with the shopping list.
Ada:
Ketchup; Tomato soup; 1 loaf of bread; 2 litres of milk and 6 packs of cheesy puffs.
Voice over:
And so on for all the simple tasks that together make up shopping.
Once you break it down into things a computer can understand鈥 it鈥檒l get right to work!
Ada:
Err 鈥 where鈥檚 the shopping?
Voice over:
But remember鈥 Computers can鈥檛 think for themselves, so when you decompose your task, you have to get it right. When you decompose a problem, you can鈥檛 miss anything out!
So there we go. Decomposition. Break the task down into smaller, simpler tasks that the computer can process. And the best thing about computers is鈥 They can鈥檛 eat your cheesy puffs.
Decomposition - Breaking big tasks down into smaller ones.
Video summary
A teenage programmer discovers how decomposition works through trial and error.
She tries asking her computer to go shopping for her but he doesn't understand.
She realises she has to break down the task into a list of simple instructions to follow.
With a clear set of ordered instructions, the computer goes to the shop, collects the items, pays for them - but returns without them.
The programmer has forgotten to tell him to bring the shopping home in her instructions.
She amends her code, including all the necessary instructions.
These clips are from the series How to Think Like a Computer.
Teacher Notes
This could be used to explore algorithms through working out steps in a process, once this is done students could then write the algorithm out in pseudo code or as a flowchart.
This could be linked to an explanation of binary, as computers need everything broken down into simply, such as in 1鈥檚 and 0鈥檚.
You could ask students to think of everyday situations and then write algorithms through decomposing the situation or problem.
Students could discuss the contributions of women in IT such as Ada Lovelace, as the main character is called Ada.
This could be used to discuss whether computers think?
Do humans think?
This clip will be relevant for teaching Computer Science at KS3 and KS4 in England, Wales and Northern Ireland and National 4 and 5 in Scotland.
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