Math multiplication


A good starting point for math multiplication is learning how to multiply whole numbers.


Multiplying single digit numbers


If you know your multiplication tables (times tables), then you know how to multiply single digit numbers.


You can learn your times tables here.


Multiplying numbers with more than one digit


Perhaps the easiest way to multiply multi-digit numbers without a calculator is to use the grid method (box method).


This involves breaking down numbers with more than one digit into units, tens, hundreds, thousands etc.


Consider the example 18 x 3


Here's the grid for this multiplication



What are the steps involved in forming this grid?


First split 18 into 10 plus 8 - enter these figures across the top of the grid.


Leave 3 alone and enter it down the left side of the grid.


Next multiply each set of numbers

10  x  3   =   30

8  x  3   =   24


Finally add the results of these multiplications

30  +  24   =   54


You now have your answer

18  x  3   =   54


How about 25 x 14?


Splitting 25 and 14 gives 20 + 5 and 10 + 4.


Enter these figures across the top and down the left side of the grid.


Multiply each set of numbers

20  x  10   =   200

5  x  10   =   50

20  x  4   =   80

5  x  4   =   20


Add the results of these multiplications

200  +  50  +  80  +  20   =   350


So

25  x  14   =   350


And 421 x 28?


Don't worry - it's not as complicated as it looks!



First split 421 into 400 plus 20 plus 1 - enter these figures across the top of the grid.


Now split 28 into 20 plus 8 - enter these figures down the left side of the grid.


Multiply each set of numbers

400  x  20   =   8000

20  x  20   =   400

1  x  20   =   20

400  x  8   =   3200

20  x  8   =   160

1  x  8   =   8


and add the results

8000  +  400  +  20  +  3200  +  160  +  8   =   11788


Therefore

421  x  28   =   11788


Or use your calculator!


For example, enter 421, press the multiply sign (x), enter 28, press the equals sign (=) to give

11788


You've confirmed 421 x 28 = 11788!


Practice math multiplication using the grid method and your calculator


Hopefully you can see that multiplying numbers with more than one digit isn't difficult.


Now choose some of your own multi-digit numbers, multiply them using the grid method, then check your answers on a calculator.


More more on multiplication click:

Multiplication tables (times tables)

Multiplying fractions


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