Which of the following numbers is 12 less than negative 3.2? Circle your answer. The options are negative 16.2, negative 8.8, 8.8, and negative 15.2.
We look at the question. It says that we’re looking for the number that is 12 less than negative 3.2. Well, first of all, we’re looking for a number that is less than negative 3.2. So therefore, we could rule out 8.8 because 8.8 is positive, so therefore must be greater than negative 3.2. So what we can do is we could do negative 3.2 minus 12 to work out what 12 less than negative 3.2 is. That’s because we’re gonna subtract 12 away cause we want 12 less than it. And this will give us negative 15.2. And we could do this on a calculator.
We’re gonna also have a look at our number line to see how it work. Well, if we have negative 3.2 and we want to find a number that is 12 less than it. Well, 12 less than it means that it’s become more negative. So therefore, we’re gonna go to the left. Because if we subtract from a number, then we move to the left on our number line. So therefore, if we subtract 12 or move 12 units to the left, we go from negative 3.2 to negative 15.2. And we could have done that mentally because we know that as we move to the left, it’s gonna become more negative. So therefore, if we add 12 to 3, we get 15. So it’s gonna be negative 15. And then we’ve got our .2, so negative 15.2.
So therefore, we can say that the correct answer is that negative 15.2 is 12 less than negative 3.2.