456
123
———
333
Multiplication is to put every bit in the ten digits first: 12* 1 1.
12
1 1
———
12
12
—————
132
For division: If 25.5 is divided by 3.
3*8=24 3*9=27, so multiply 8 to get 25.5-24 =1.53 * 0.5+1.5, so the answer is 3.5.
Follow the above exercises. I believe your book is more detailed than mine. Practice more and you will know better than anyone else!