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Ordering expressions

Let's get some practice thinking about adding and subtracting variables representing positive and negative numbers on the number line.

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• At , if a is -0.7 and b is -0.2, lets say, then, -0.7-(-0.2) = -0.5 (a-b) which is definitely, bigger than a and -0.7-0.5, would be -1.2, which is smaller than a. So, can someone please explain
• Yes, a-0.5 is smaller than a, and a is smaller than a-b. So it is ordered from least to greatest as a-0.5, a, and a-b. That's what Sal wrote. He didn't switch around the three blocks for technical reasons, which he explains at .
• when will we have to use this i the real world?
• when am i going to need to know how much john earns in a week if he earns 2 dollars on monday and 4 dollars on the other days? castle in the mist #3
• He talks so slow I watch this at 1.5x speed
lol
• At i tested that logic and its not true. Or am I getting it wrong? Like if i substitute q with -10 and n with -2 my expression will be -10-(-2) = -8. So I'm not getting +ve as Sai explained that it doesn't matter. Or how am i to approach his logic?
• Now look, you substituted -10 for q and -2 for n. But the thing is that q on the number line is a positive number for you can't substitute with a negative.
• Is dream a life or is life a dream
• Life is dream
• I'm only a 6th grader, and I am wondering, if a and b are both negative numbers, and a-b is technically adding to a, would a+b be subtracting from a, making it a smaller number?
• If a and b are both negative numbers then yes adding a+b would be subtracting the smaller one from the larger one making it a smaller number. For example if a= -5 and b= -2 then a (-5) + b (-2)would be a (-5) - b (-2) which would equal -7.
(1 vote)
• why does adding a negative number to a negative number equal a positive number?
• We can represent "removes" by a negative number and figure out the answer by multiplying. This is an illustration of a negative times a negative resulting in a positive. If one thinks of multiplication as grouping, then we have made a positive group by taking away a negative number twelve times.