What Do My Grandma’s Braided Bread and Decomposition Have in Common?
Computational thinking: decomposition
My fondest childhood memories begin with me opening the front door at the end of a primary school day. I would be enveloped by the warm comforting smell of buttery braided bread. Instantly, I knew our grandparents had arrived for another surprise visit.
For my 10th birthday, I asked my mum if she could make the delicious bread. She called my grandmother to ask for the recipe. “Oh dear, I have no idea how to make that bread. I’ve never had a recipe.” My mum, not inclined to disappoint me, asked my grandmother to solve the “braided bread recipe problem” using decomposition.
precise, unambiguous, step-by-step instructions
What is decomposition? Put simply, decomposition is the ability to break down a problem or task into precise, unambiguous, step-by-step instructions.
Now, a nerdy example. Three children are playing a game with two dice. The first child rolls the dice, then all the children say a number as fast as they can. Usually, the first child who says a number wins, but not always. Each child playing copies what the first child did. After you watch the game for a bit you begin to deduce the steps of the game:
Step 1: One child rolls two dice
Step 2: All the children multiply the two rolled numbers as fast as they can
Step 3: The first to say the correct answer wins that round
Step 4: All the children take a turn
This act of figuring out the steps is decomposition.
connection between algorithms and decomposition
Readers of last week’s article on algorithms, may have already ascertained the connection between algorithms and decomposition. Decomposition helps you deduce the steps needed to solve a problem, complete a task, or determine an algorithm. Next time you order the usual, watch your barista to try and learn how your beverage is made. Use your decomposition skills to figure out the unambiguous, step-by-step instructions you can mimic at home.
How was the “braided bread recipe problem” solved? My mum asked my grandmother to bake the bread and carefully write down each step. It took a few tries but my grandmother was eventually able to mail my mother the precise step-by-step recipe instructions. The birthday bread was nearly perfect, but not quite the same. There was something special my grandmother always added to everything she ever made for us — you can probably guess what that is — and that ingredient is impossible to decompose.
