How to Subtraction Decimals Using Left to Right Method

In this lesson, we will learn how to subtract using the left to right subtraction method when it comes to decimals. We’ve been asked to subtract from 5.7. We need to take away 2.13. So when we write this down, I've got 5.7 and 2.13. This has got two decimal places. This has got one so let’s make them the same. So 5.70 minus 2.13 is what we need to find out. So here’s what we do.

We write this down, 5.70. Write the largest number down first. Step one, we subtract the ones part. What is the ones part of 2.13? Actually let me do this. Let’s break down 2.13 into 2.00 plus 0.10 plus 0.03. This is the ones part. This is the tenths part and this is the hundredths part, 2.00 +0.10+0.03. So this is what we’re going to keep in mind. So from 5.70, let’s first subtract the ones part which is 2.00. What do we have left?

Now let’s subtract the tenths part. So what do I do? I take away 0.10 so 3.7 minus 0.10 is 3.6. Next we take away the hundredths part. So from this we take away 0.03 so obviously I cannot subtract 3 from 0 so I’ll trade ten minus 3 is 7, 5 to take away 0 is 5 and 3. So what are we left with? So the answer is 3.57.

Remember all we did was take away one piece at a time. First we subtracted the ones part so we took away two, that I could in my head. Then subtract the tens part then subtract the hundredths part.