How To Subtract Decimals
Question
The key to subtracting decimals is that the ___________ is in the right place.
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Hi, I'm Peter Edwards from Bluetutors. We teach children of all ages, right from primary school to degree level, and we find the highest quality tutors. Today, I'm going to teach you some maths. We're now going to learn how to take one decimal number away from another, subtract decimals. What is important to realize is that this is no more complicated than taking away another which hasn't got any decimal places in it from another number which has no decimal places in it. It's all about making sure you get the point in the right place. So we're going to start with a fairly straightforward example. We're going to look at zero point four five six, minus zero point one two three. As you would with any other number, you put the first number at the top, and the second number at the bottom, and we're going to do subtraction. It's important to know that the points are above each other, that's the most crucial thing when you're doing a sum like this. So six minus three is three, five minus two is three, and four minus one is three. You put the points at the bottom, and obviously zero minus zero is zero. So you can see the results of that sum. We'll move on to a slightly more complicated example, and you'll see why that's so complicated. Zero point three nine one, and we're taking away zero point two six eight. So what I'm going to ask you to do here, for good practice, is put the point at the bottom. So, you know it's just always going to be there. Okay, so, we now have one minus eight, which normally would give us minus seven, but that's not something we're going to do. As you would in any other subtraction sum, you're going to take a number from here, change that to eight, and put the one there to make that eleven. So, eleven minus eight is three, eight minus six is two, and three minus two is one. So point three nine one minus point two six eight gives you point one two three. Okay, so now we're going to look at another example, which again, will have an extra step. So, again, make sure we put the point underneath the point in the top number. Now we have four, two, one. You'll see that there's a space up here. What you should do there is put a zero, just to complete the sum. So, were going to take those away from each other, similarly to what we did in the second example, we're going to cross out the four and make that a three, and make that ten. So ten minus one is nine, three minus two gives us one, five minus four is one, we put the point in, and two minus one gives us one. So, two point five four minus one point four two one equals to one point one one nine. That is how to subtract your numbers when they are decimal numbers. .