deduction

Everyday

1. An amount taken away from a total (a deduction from your pay). tree →
2. Working something out by reasoning from facts you know (Sherlock Holmes's deductions). tree →
3. A conclusion you reach that way. tree →

In the lessons

In maths: deductions of money or points mean subtraction. In science and detective stories: deduction from clues; logical reasoning in maths proofs. Phrases: tax deduction, powers of deduction, by deduction.

Examples

• After the deduction of tax, he got 300 pounds. tree →
• The detective made a clever deduction from the muddy boots. tree →
• By deduction, the missing number must be 7. tree →
• There's a 5-point deduction for every mistake. tree →
• Good scientists use deduction and evidence. tree →
• Your deduction was correct! tree →

Note

Two meanings from two verbs: deduct (take away) and deduce (work out). In word problems, «a deduction of 20» means subtract 20.