Using the method discussed above, determine the answer to the following question. So here it's 8.17×108 + 1.25×109. 109 is the larger power, so that's the larger value. So that would mean that we need to convert the smaller value to match that same exponent.

So here we have 108:00, so we need to increase it by one. Now if we're trying to increase the exponent by 1, so we're going to increase by 1. That means that we're going to have to decrease your coefficient by 1 decimal place. So remember, there is a reciprocal or opposite relationship between your coefficient and your exponent. Whatever happens to one, the opposite happens to the other.

So we're going to need to make this number, this coefficient value smaller so that my power of eight can increase to become the power of nine. So I'm going to take this decimal. I'm going to move it over 1 so that we go from 8.17 to 0.817, and by baking that smaller, this just became larger, so plus 1.25×109. Now that both of them have the same exact exponent, I can finally add them together.

The exponent stays constant and all I'm doing now is I'm adding 0.817 plus 1.25. So when I add those two together it gives me 2.067×109. But remember, when we're adding or subtracting coefficients, we want the least number of decimal places. So for the first value we have 3 decimal places. Remember, decimal places are the numbers to the right of the decimal point. This has three decimal places. This here has 2 decimal places.

So my answer at the end must have two decimal places total. So we're going to have to round this to 2.07 and it'll be ×109. So that would be my final answer here. Follow the rules that we observed up above.