How do you model -9-(-4) with interger chips

Explanation:

Start with 9 negative chips, for a value of -9.

Take away (subtract) 4 of the negative chips. This is modeling - (-4).

You will be left with 5 negative chips.

  -9 - (-4) = -5

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Each negative chip in this scenario models -1. The actions you're doing with the chips are full equivalent to the actions you would do for the subtraction problem 9 - 4 = 5, except that the numbers (chips) are negative, not positive.

$20.01

step-by-step explanation:

the sale price is (1.00 - 0.77)($87), or 0.23($87), or $20.01.