1.239 rounded to 3 significant digits is 1.24
555
To round to the nearest hundred and ten both being 200 it leaves 9 possibilities. 195,196,197,198,199,201,202,203, and 204. The only one with digits adding up to 19 is 199.
-12
3
100 (rounded up to the nearest 200).
199
10 (565,566,567,568,569,570,571,572,573,574)
The number would be 2666. 6 is repeated 3 times. Rounded to the nearest hundred is 2700 and rounded to the nearest thousand is 3000.
The first ten digits of pi are 3.141592653. If rounded to the nearest billionth, that last digit would be 4 instead of a 3.
686.88 rounded to 3 significant digits is 687
1.239 rounded to 3 significant digits is 1.24
The thousandths place is the third digit after the decimal point. 86.255 only has 3 digits after the decimal point so it is already (possibly) rounded to the nearest thousandth.
555
555
3.12 rounded to the nearest tenth is 3.1. Rounded to the nearest one is 3. Rounded to the nearest ten is 0.
To round to the nearest hundred and ten both being 200 it leaves 9 possibilities. 195,196,197,198,199,201,202,203, and 204. The only one with digits adding up to 19 is 199.