Hector\'s method:

whichever number is bigger it gets two signs of its own while the smaller number gets a single sign of it\'s own.

Example one:

35 + (-24)

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The 35 gets two positive signs because it is bigger than 24.
Circle two signs that are closest to each from each part of the problem
if the circle has two of the same signs than you add if the signs are different that you subtract.
whatever sign is left outside the circle is what your answer should have by it

35 + (-24)= +11

Example two:

-84 + (-15)

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the 84 gets two negative signs because it\'s bigger
the circle has two negatives so adding the 84 and 15 will give us the answer
the sign that is left outside the circle should be a negative sign the answer will have a negative sign

-84 + (-15)= -99

Elementary Mathematics