4000÷10×2+4-8 rounded to the nearest ten

4000 ÷ 10 × 2 + 4 - 8 = 796 

REMEMBER THE ORDER OF OPERATIONS TO DO THIS. I ATTACHED AN IMAGE BELOW.

STEPS:

× 2 + 4 - 8
× 2 Here, we ignore the "4 - 8"
400 × 2 = 800
Now, we get the "4 - 8" back. 
800 + 4 - 8 = 796

796 ≈ 800
We round the number to the nearest NEXT ten if the last digit is 5, 6, 7, 8 or 9. The 6 in "796" is the reason we move to the NEXT digit in the tens place, (there's no tens after 796); so it's 800.

2hours and 184 miles