948 or 9.48 x 10^2
There are two sets of rules for significant figures
• One set for addition and subtraction
• Another set for multiplication and division
You used the set for multiplication and division.
This problem involves addition and subtraction, and the rule is
The number of places after the decimal point in the answer must be <em>no greater than the number of decimal places in every term</em> in the sum.
Thus, we have
78.9
+890.43
-21.
= 948.33
The "21" term has the fewest digits after the decimal point (none), so the answer must have no digits after the decimal point.
To the correct answer is 948 = 9.48 x 10^2. It has three significant figures.
When’s I would like to say that it may be B because
Most of the surface of the earth is covered with water and looks blue from space.
Answer:
You are not using properly the function exponential in your calculator
Explanation:
When a number is too big or too small we use scientific notation. This is a number between 1 a 10 multiplied by a power of 10.
When you are writing 4.5*10^-9 you are actually writing 0.0000000045 in scientific notation.
When you enter this in the calculator you have to use the function EXP after the first two numbers.
Steps: 1) Enter 4.5
2) Enter EXP
3) Enter minus (-)
4) Enter 9
