0.42857
by using decimals
1.239 rounded to 3 significant digits is 1.24
686.88 rounded to 3 significant digits is 687
It is: 2.360
It is 4730.
5.60
2.56
Rounded to the nearest tenth, there can be only one decimal. And that is 7.8
There are five significant digits.
2.641, 2.642, 2.643, 2.644
100 (rounded up to the nearest 200).
It is 1570000 rounded to 3 significant figures