Elaine used the subtraction algorithm to subtract −17−(−3). She got the answer −14, but she does not feel confident that she is correct. Connect the expression −17−(−3) to a two-color counter model. Explain how the two-color counter model can be used to confirm whether Elaine’s answer is correct.(2 points)

Question

-17 is blue and -3 is red

Answer 1

To use a two-color counter model to confirm Elaine's answer, we can use blue and red counters to represent -17 and -3, respectively.

First, we start with -17 blue counters. Then, we subtract -3 red counters from the -17 blue counters.

To do this, we remove 3 blue counters (since -3 is red) from the pile of -17 blue counters. After removing the 3 blue counters, we should have -14 blue counters remaining.

If our resulting pile matches the answer that Elaine got (-14), then her answer is correct. If there is a different number of blue counters remaining, then her answer is incorrect.

Therefore, by representing -17 as blue counters and -3 as red counters, we can physically demonstrate the subtraction process and visually confirm whether Elaine's answer is correct.