Question

Help with number 11-please

Answer 1

Step-by-step explanation:

11.

-165 + 3217 + 65

what I see right away is the equality of the 2 digit positions between -165 and +65. I can immediately combine them to -100.

and then the rest is easy : 3217 - 100 = 3117.

173 + (-43) + (-97)

I see that -43 and -97 combine nicely too: I can take the -3 of -43 and add this to -97, which gives me -100, while it leaves -40 on the former -43 side. it is now easy to combine these to -140.

and 173 - 140 is again easy to calculate : 33