How to multiply?

Get a ruler in your hands. Measure things until you start to understand how a ruler works. Measure some stuff and figure out where the center is. Say you measure a book and it's 7/8" thick. You look at your ruler and see that every eighth is divided into two sixteenths, so obviously half of 7/8" is going to be 7/16". If you write that out you have 1/2 x 7/8 = 7/16. And you notice that 1/2 is divided into 2/4 and then into 4/8 and so on, so you can convert anything to anything by multiplying all the numbers on top and then all the numbers on bottom.

Other rulers are divided into 10 and 100 parts. But an inch is still an inch, so anything on one ruler can be translated to the other ruler. A half inch on one ruler is 5/10 or 50/100 on the other. An eighth inch is just 12.5 marks when you have 100 marks per inch. A metric ruler divides an inch into 25.4 parts, so a half inch would be 12.7 of those parts. Pretty simple, isn't it? Practice this a bit and people will think you went to wizard school.

Multiplication: Get a bunch of buttons or pennies or something. Lay two buttons on the table, and then lay two more so you have a square. Count all the buttons in the square. You should have four. So we say four is a square number and its root, its side, is two. Thgat is to say two times two equals four. You can do this to find other square numbers.

Lay three rows of two buttons and count them. You should have six. So that means two times three equals six. It also means three times two equals six. Two and three won't ever multiply to give you any other number, only six. You can do this again with three rows of four buttons, and so on.

Eventually you write a list of times tables. Across the top label the columns 1 through 10. On the left side label the rows 1 through 10. In each space write the product of the row and the column. Memorize this completely.