Question Video: Finding the Difference of Rational Numbers Given in Different Forms | Nagwa Question Video: Finding the Difference of Rational Numbers Given in Different Forms | Nagwa

# Question Video: Finding the Difference of Rational Numbers Given in Different Forms Mathematics • 7th Grade

Consider that π₯ = 3/4 and π¦ = 30%. By converting both π₯ and π¦ into decimal form, find the value of π₯ β π¦ in decimal form.

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### Video Transcript

Consider that π₯ is equal to three-quarters and π¦ is equal to 30 percent. By converting both π₯ and π¦ into decimal form, find the value of π₯ minus π¦ in decimal form.

In this question, we are asked to find the difference between two rational numbers, one given as a fraction and the other given as a percentage. It is always a good idea to write both numbers in the same form to make the subtraction easier. Usually, we would rewrite the numbers to be in a fractional form. However, we can also do this by rewriting both numbers into a decimal form.

Letβs start by converting three-quarters into a decimal. There are many ways that we can do this. For instance, we may just recall that three-quarters is 0.75. However, if we cannot remember this conversion, we can always rewrite three-quarters as an equivalent fraction with a denominator of 100 by multiplying the numerator and denominator by 25. We see that three-quarters is equal to 75 over 100. We can easily convert this fraction into a decimal by moving its decimal point two spaces to the left. We see that three-quarters is equal to 0.75.

We can follow a similar process for 30 percent. We recall that percentages are measured out of 100. So 30 percent is the same as 30 over 100, which we can convert into the decimal 0.30, which is just 0.3. We can now substitute our decimal conversions of π₯ and π¦ into the expression to see that π₯ minus π¦ is equal to 0.75 minus 0.3. Finally, we can calculate that 0.75 minus 0.3 is 0.45.

It is worth noting that we can see this from our fractional conversions as well. We have 75 over 100 minus 30 over 100 is equal to 45 over 100, which is equal to 0.45.