(12) Make certain students remember how to make corrections when practicing Rocket Math. Display these 18 x 24 inch posters on the walls in a dozen classrooms and use it to teach students how to make those all-important corrections for errors and hesitations. A $216 value. Three step procedure: (1) STOP! The student who is checking states the problem and the correct answer. (2) REPEAT. The student who is practicing repeats the problem and the answer three times. (3) BACK UP. The student who is practicing backs up three problems and continues practicing.