Koplow Games Subtraction dice set is perfect to improve the math fluency of your kids. Includes 10 pieces for fun way to learn basic math. Learn to subtract basic -1 through -6 with dice. Measures 16 mm and white in color. Suitable to use for learning centers or group activities. Ideal for the age group of 6 - 9 years/grades kindergarten - 3rd. Warning choking hazard: Small parts, not for children under 3 years. Each individual set contains 10 Dice, Bundle of 4 sets, 40 Dice total.