Student Projects/Multiplication- STAR Technique

This technique is simple combination of multiplication and addition simultaneously which we do separately in normal method. Use this method we should be very quick and precise with multiplication tables.

Suppose we need to multiply 27 with 83

Step 1: Write in this format

2     7

8   3

Step 2:  Now multiply digits in the ones place

7x3=21

Write ‘1’ in ones of product and carry over ‘2’ to next step.

2      7

8      3

        1

Step 3:  Now cross multiply digits in one place and tens place and add the result to the carry over digit

2x3=6

8x7=56

6+56+2=64

Write ‘4’ in tens of product and carry over ‘6’ to next step.

2       7

8       3

4 1

Step 4:  Now multiply digits in the tens place and add the result to the carry over digit

2x8=16

16+6=22

Since each digit is multiplied with every other digit we can write ‘22’ directly without any carry over.

2       7

8       3

2 2 4 1

One advantage of this method is we can finish this calculation in one line and if we are interrupted in between calculation, we can resume back looking at the number of digits we have written in the product.