This question is easy once you understand. So when adding, subtracting, multiplying, or dividing with whole numbers you turn it into a fraction. So 12 is going to become 12/1. 8 1/8 is a mixed number so we have to turn it into an incomplete fraction. Here is how you do it. Multiply the denominator by the who number. So 8 x 8 = 64. Then you add your product to the numerator, which will make it 65. Then after this you keep your denominator giving you 65/8. Now we have to find the common denominator by finding the LCM. So the LCM is 8. Next we divide the old denominator by the new denominator. So 1 goes into 8, 8 times. And next 8 x the numerator. so 8 x 12 = 96. We do the same to the other side. Now we have 96/8 - 65/8 = 31/8. Finally we make this a mixed number. So 31 divided by 8. So you should get 3 7/8.