0.3333333333 (3's forever) rounded to the nearest thousand:
0.3333333333 = 0000.33333333333
The left-most 0 is in the thousands place. The next digit over is the 0 in the hundreds place. Because that digit (0) is less than 5, the 0 in the thousands place does not round up to 1. We have a 1 in the thousands place and everything to the right of that just becomes 0s.
Result: 0000.333333333 becomes 0000.00000000 or just 0.
Answer: 0
.
If you meant "round to the nearest thousandth," then:
0.33333333 (3's forever)
Counting from the left, the third 3 is in the thousandths place. One digit to the right, in the ten-thousandths place, is another 3. Because that digit (3) is less than 5, the 3 in the thousandths place does not round up to 4.
Answer: 0.333