How can you use the fact 11 x 5 equals 55 to solve 11 x 6?

Multiplication is simply repetitive addition. For instance, the expanded form of 2 * 3 is: 2 + 2 + 2, or 3 + 3. The expanded form of 5 * 6 is: 5 + 5 + 5 + 5 + 5 + 5, or 6 + 6 + 6 + 6 + 6. From the information above, it is evident that 11 * 5 = 11 + 11 + 11 + 11 + 11, and 11 * 6 = (11 * 5) + 11 So, substitute 55 for 11 * 5: 11 * 6 = 55 + 11 11 * 6 = 66