substitution
part of speech
noun (a substitution, substitutions; substitution, uncountable)
meaning for a pupil
1) A substitution is putting one person or thing in the place of another. tree →
2) (sport) A substitution is when a player is taken off and another player comes on. tree →
3) (maths) Substitution means replacing a letter in an expression or formula with a number, to work out its value. tree →
4) (cooking) A substitution is using a different ingredient instead of the one in the recipe. tree →
sense in the lessons
In maths lessons substitution is a key algebra skill: «If a = 3, find 2a + 1» — you substitute 3 for a to get 7. In science, a substitution reaction swaps atoms. In sport it is changing players. In codes, a substitution cipher swaps letters for other letters. Phrases: make a substitution, by substitution, substitution cipher.
examples
- The coach made a substitution at half-time. tree →
- By substitution, if x = 4, then 3x = 12. tree →
- Use substitution to check your answer to the equation. tree →
- We used honey as a substitution for sugar. tree →
- In a substitution cipher, A might become D and B might become E. tree →
- Two substitutions changed the whole match. tree →
- Substitution of the ingredients made the cake taste different. tree →
note
Verb substitute: you substitute the new thing FOR the old one (substitute 5 for x). In maths, put brackets when substituting negatives: if a = −2, a² = (−2)² = 4. Countable for single changes (two substitutions).
Trees and pragmatics
Every meaning and example of «substitution» parsed by Mova, each sentence with its dependency tree and frames.