substitution rule
nounUK /ˌsʌbstɪˈtjuːʃən ruːl/
US /ˌsʌbstɪˈtuːʃən ruːl/
A substitution rule is a rule that says you can swap one thing for another thing.
The teacher explained the substitution rule so we could replace x with 5 in the math problem.
RELATED WORDS
OTHER MEANINGS
2. In math, a rule that lets you put a number or expression in place of a letter or symbol.
Using the substitution rule, we put 3 in place of y.
3. In language, a rule about using one word or sound in place of another.
The substitution rule helps us change 'he' to 'she' in a sentence.
4. In sports, a rule about when a player can be replaced by another player.
The substitution rule says each team can make three player changes.