Multiplying by two is quite simple, the rule is following the pattern we saw when multiplying by twelve and multiplying by seven but this time the neighbor is ignored.
The Rule For Multiplying By Two
- Double the number.
We will still look at an example, as we are only interested in the number we will shrink our red box to just cover the number we are looking at.
An Example - Multiplying 483 By 2
For our example we will look at 483 x 2 and we will set it up as we have done previously.
Placing our red box over the last digit to the right, we have the number 3. So we double it to get 6 which we write.
Moving the red box to the left we now are looking at number 8, doubled is 16 so we write 6 and put a dot above it to indicate the 1 that we need to carry.
Moving left again we come to the number 4. We double it to get 8 then add the 1 from the carry to give 9, which we write.
In this case the last step involves doubling zero which is still zero so we ignore this step and our equation is complete and the answer is 966.
Practice Multiplying by Two in your Head
To help speed up your mental calculations it helps if you can simply look at a digit and instantly know the double value. For most people this will take very little practice.
Your conscious thought should be something like 6 ... 12, not something like 6 ... 6 times 2 is ... 12.
If you have any comments or questions please leave a comment below.