Answer: The correct number is 0.
Step-by-step explanation:
2+0 = 2
2+0 = 2
2+(-2) = 0
0+0 = 0
0+0 =0
Estimation:
23 --> rounded to 20
71 --> rounded to 70
70 + 20 = 90. I rounded both numbers down so the exact sum must be only a little greater than my estimate.
Top left : Unlike the others it is not displayed in a numerical form.
Bottom Left : It is the only item that goes above 1/100%.
17, 29-5=24
24/2=12
12
12+5=17