myfreemathworksheets.com › grade-6-mental-mathsGrade 6 Mental Math Worksheets | Free Printables - FMW Multiplying by 10, 100 and 1000 should be taught first and then should be practised during mental math. Add these questions into your daily warm up and your class will improve in no time! For more grade 6 mental math worksheets, check out Math Salamanders. They have plenty of great free mental math worksheets for sixth grade.