2+2=4
Two and two is/are four. (informal)
Two plus two equals four. (formal)
9-4=5
Four from nine is/leaves five. (informal)
Nine take away four is/leaves five. (informal)
Nine minus four equals/is five. (formal)
5x4=20
Five fours are twenty. (informal)
Five times four is twenty. (informal)
Five multiplied by four equals twenty. (formal)
15:3=5
Three(s) into fifteen goes five (times). (informal)
Fifteen divided by three equals five. (formal)