decomposition

Everyday

1. (science) The natural breaking down of dead plants and animals into simpler things, by bacteria, fungi and worms; rotting. tree →
2. (maths) Breaking a number or shape into smaller parts (partitioning). tree →
3. (science) The breaking of a substance into simpler substances by a chemical reaction. tree →

In the lessons

In science: decomposition returns nutrients to the soil; decomposers such as fungi do it; compost heaps. In maths: number decomposition, like 47 = 40 + 7, or breaking a shape into rectangles to find area. In chemistry: thermal decomposition.

Examples

• Fallen leaves turn into soil by decomposition. tree →
• Worms and fungi help decomposition. tree →
• Decomposition is faster when it is warm and damp. tree →
• Use decomposition: 36 = 30 + 6. tree →
• We used decomposition to find the area of the L-shape. tree →
• Heating some rocks causes thermal decomposition. tree →

Note

Verb: decompose; decomposer is a living thing that breaks down dead matter. In maths, decomposition does not change the total: the parts add back to the whole. «Decomposition» in subtraction (UK) also means exchanging a ten for ten ones.