sometimes we find it difficult to do long multiplication because after multipling a number we forget what we need to add to the answer of the next. e.g 234 X 7 when we do 7X4 = 28 we might need to write down 8 and keep 2 till we multiply 7X3 this is cumbersome.
this has made me come out with the following; if we start with 7X2 and write the complete answer 14 and then 7X3=21 and 7X4= 28 and arrange them as follows as we get the answer:
ABCD
14
+21
+28
...........
1638 BECOMES THE ANSWER ADDING FROM RIGHT TO LEFT.

THIS IS AKATAMAX MULTIPLICATION RULE WATCH OUT FOR MORE.
have you tried it? if not go on increase d numbers you will see it works. I AM STILL WORKING ON IT TO SEE HOW IT CAN BE EASIER.