Answer:
"between 2 and 8" or, "less than 3.3", or "bit less than 3", or by long division, 2.984, depending on how accurate your evaluation is needed.
Explanation:
How rough do you want your extimate?
A wild guess is "something between 1 and 8, since 1.4 is between 1 and 2.
Something better? that's a bit less than 1.5, which means 3/2. Cubed, it's 27/8. so it's less than 3.3
More accurate? it's 14/10, or 7/5. Cubed, 373/125, which is almost 375/125, or 3. So as a wild guess, it's 2.9
Exact value, you do long division with the previous value, 373/125, and you get your result"