Estimate: 55 +8
50
60
7
8

But the actual solution is 63.

Step-by-step explanation:

55+8=63

63

3<5 so you don't round up, you round down.

Rounding down... 60

60

But the actual solution is 63.

at 0 hours the plane has 422,000 gallons of gas.

after 2 hours it has 369,250 gallons.

subtract to find the difference and then divide by 2 hours:

422000 – 369250 = 52750 /2 = 26,375 gallons per hour.

can also do the full 16 hours:

the plance used 422,000 gallons in 16 hours:

422,000 / 16 = 26,375 gallons per hour.