TenMarks teaches you how to subtract positive and negative decimals.
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Learn about Subtraction of Decimals Let’s learn about subtraction of decimals. We’ll do two problems and learn through them. The first problem is 534.67-267.23. Now we’ve got one number, and we’re taking away the second number from it or subtracting 267.23 from 534.67. It’s a subtraction operation. Now key is again, like with addition, we need to make sure that both have equal number of digits after the decimal spot. In this case, this number has got two digits after the decimal, this one as well. So we’re okay on this front. Second is we always place the larger number on top and subtract. And we align. So we’ll place 534.67 aligned it with 267.23 so that the decimals are right on top of each other and we’ll just subtract it. 7-3 is 4, 6-2 is 4. 4-7, I’ll have to borrow 1, so this becomes 2. And I borrow 1, 14-7 is 7. 2-6 can’t be done so we’ll borrow 1 again. 12-6 is 6, 4-2 is 2. So the end result is 267.44. That’s what we were looking for from the first solution. The second solution, or the second problem is a slightly bit more interesting one. Which is -5.23 added to 9.1. Now the key to remember is if the signs of the two numbers are different, it is a subtraction operation. Let me take some more space and explain what I mean. So the way we do this is again, we follow the same principle. First number is 5.23, the second number it needs to have two digits after the decimal. So let’s call it 9.10. Now that the first condition is satisfied, we place the larger number on top. 9.1 is greater than 5.23. So 9.10 and 5.23 and then we subtract, 10-3 is 7, 10-2 is 8, and 8-5 is 3. So the end result is 3.87. One additional thing to remember is the sign of the result will always be the sign of the larger number. Here the larger number is 9.10 that had a positive sign. This had a negative sign, so this will always have a positive sign. That’s how we subtract decimals.