Multiplication....sigh.....

My kids have such a hard time with multiplication of multi-digit numbers because of all of the steps to remember.  I found a new method to teach kids how to multiply multi-digit numbers in a snap.  Don't believe it?  I didn't either, but I was willing to try anything.

Traditional multiplication has so many steps involving multiplying, adding, and place value.  It's just too much for my kiddos.  So, I went searching and found a new method!

Not only does it work, but the kids LOVE it!  Here's a brief summary of how it works.  I will warn you, since you learned to multiply "the old way"  it may take your brain a few tries to understand this method.

Step 1:  Change the way you write the problem.  Let's use the problem 54x72

Step 2:  Simple multiplication.  You will multiply 7x5 and put the answer in the first box.  The slash separates the tens and ones.  Then you multiply 7x4.  It will look like this.

You continue to the second row and multiply in the same manner.  2x5 and 2x4.  Since 2x4=8, you will need to put a 0 in the tens place.  It will look like this when you are finished multiplying.

Step 3:  Add on the diagonal.  I give the kids a sticky note to help them block off numbers they are not adding to help keep them from getting distracted from extra numbers.

We begin adding at the bottom right.  This number will be the ones place.  8

Next add 0+0+8=8 (Tens place)

Next add 1+5+2=8  (Hundreds place)

The 3 is moved to the thousands place.  The final answer is 3, 888.


Let's do another one.  78x45  This is what it looks like after you multiply.

Now, you add.  This time, we will need to "carry" since our sums will be more than 9.  Starting with the bottom left, the ones place is 0.

The tens place is 1 carry 1 ten over (5+4+2=11)  Here's the only tricky part.  Write the 1 down in the tens place for your answer and carry 1 up to the next row.

The hundreds place is 15 (3+8+3+1)  Here's the only tricky part.  Write the 5 down in the hundreds place for your answer and carry the 1 up to the next row.  Here's what it looks like.

Finally, you add 2+1.  3 is the thousands place.  The final answer is 3,510

Pretty cool, huh?  I have a step by step smartboard file that you can use to teach your class this method. You can find it HERE if you are interested.