Express the difference of 7.69 and 4.0 using the correct number of significant digits: 3.7
3.70
3.6
0
3.69

3.7

Explanation:

Significant figures:

All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.

Leading zeros are not consider as a significant figures. e.g. 0.007 in this number only one significant figure present which is 7.

Zero between non zero digits are consider significant such as  1004 consist of four significant figures.

The zeros at the right side such as 4500 are also significant. There are four significant figures are present.

When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places.

When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value.

Now we will calculate the difference between 7.69 and 4.0.

7.69 - 4.0 = 3.69

In given values 4.0 have less number of decimal places thus result must have only one decimal places. So we would round the result.

3.7

there is none because earth is stationary and flat.