A sign in a gas station advertises gas at the rate if $3.39 9/10 per gallon. How many dollars does a gallon cost, writing the price strictly as a decimal?

To write the price strictly as a decimal, we can drop the fraction part and just keep the number. Therefore, the price of a gallon of gas is $3.39.

To write the price strictly as a decimal, we need to convert the fraction "9/10" to its decimal equivalent.

To do this, we divide 9 by 10:

9 ÷ 10 = 0.9

So, 9/10 as a decimal is 0.9.

Now, we can add the decimal to the dollar amount given:

$3.39 + 0.9 = $4.29

Therefore, a gallon of gas costs $4.29.

To determine the cost of a gallon of gas, we need to convert the mixed number $3.39 9/10 into a decimal.

Here's how you can do it:

1. Take the whole number part of the mixed number, which in this case is $3.

2. Convert the fraction 9/10 into a decimal. To do this, divide the numerator (9) by the denominator (10): 9 ÷ 10 = 0.9.

3. Add the decimal value from the fraction to the whole number: 3 + 0.9 = 3.9.

Therefore, a gallon of gas costs $3.9 when written strictly as a decimal.