Answer:

1. 50%

2. 0.12(I can't quite see the number, please correct me if the number isn't 12)

3. 30/100 or 3/10

4. 1:5

Step-by-step explanation:

No. 1 Explanation:

To change a fraction into a percent, you need to change the fraction into a decimal first. To convert a fraction into a decimal, you need to divide the numerator by the denominator, so 1 ÷ 2 = 0.5. Once you have converted the fraction into a decimal, you can now convert it into a percent, 0.5 = 50%. Why? because you need to convert a decimal into a percent you need to multiply it by 100 or you can move the decimal place to the right 2 times. But how is 0.5 equal to 50%? 0.5 doesn't have a 0 at the end. Well since you have to move the decimal point 2 times, you need to add a 0 at the end to be a placeholder of the ones digit.

No. 2 Explanation:

In my previous explanation, I explained how you can convert a decimal into a percent, but in this case, we need to convert a percent into a decimal. Converting a percent into decimal is just converting a decimal into a percent but backwards, instead of moving the decimal to the right, you're going to move the decimal to the left 2 times, so 12% is equal to 0.12.

No. 3 explanation

To convert a decimal into a fraction, all you need to do is look at the last place value, in this case since it is a decimal the last place value is the hundredths place. So the denominator is going to be 100. The next step is to look at the decimal and identify the number, the number here is 30 so the fraction is 30/100. 30/100 can be simplified, to simplify a fraction you need to find both of the numbers GCF(Greatest Common Factor)and divide it by the numbers. The GCF of 30 and 100 is 10, so 30 ÷ 10 = 3 and 100 ÷ 10 = 10, so the lowest term for 30/100 is 3/10. If the numbers do not have a GCF other than 1, it is already in lowest terms.

No. 4 Explanation:

There is no need to explain No. 4, 1:5 is already a ratio so when you convert it into a ratio it is still 1:5.