This is the first step we take in computational thinking. First, we need to decompose, or break down, the problem into the smaller problems. Then we can solve each problem separately. This will help us to simplify complex problems into each step we should analyse. Let's look at the example of a journey to London.
Think about taking a trip from Basingstoke to London Waterloo. The steps you take from your house to the train station seem quite complex. But if you break it down to the different stages of the trip, decomposition makes it easier. You need directions, transportation, times and prices for a successful journey. Work backwards from the time you need to be in London which is 12 noon.
1. Make sure you have a paper A-Z London with the tube map.
2. Which trains get into London before 12?
3. Then think about how you would arrive at the train station. Do you need a bus, car, or can you walk?
4. Finally, you need to have enough money for your journey and a snack.
Now you have all the steps necessary to complete your journey. Decomposition ensures you have enough money, directions, transportation options and timings. You can now apply this method to computing with modular design.Text is available under the Creative Commons Attribution-ShareAlike License https://en.wikibooks.org/wiki/A-level_Computing