How to Convert Fractions to Decimals

Welcome to Math with Mr. In this video, I'm going to show you how to convert fraction to decimal. And if you take look at the top of your screen, it says divide the numerator by the denominator and round if needed. So, that's exactly what we are going to do. Now, I'm going to do few of these by hand, long division problem to show you exactly what's going on. And then the others, will give you the answer that calculator will give you and show you how to interpret everything. So, let's jump right into number one where we have 2/5 or 2 over 5. So, here again, divide the numerator by the denominator. So, 2 / 5. And this fraction is less than whole, so our decimal is going to be less than whole as well because this decimal is going to be equivalent to 2/5. So, we can't do 2 / 5, right? We can't take whole group of five out of that two, so we need to extend our division problem by putting decimal and zero. So, now we can think of that as 20. Bring our decimal straight up. How many whole groups of five can we pull out of 20? Well, four. 4 * 5 is 20. Subtract and we get zero and that tells us we are done. So, 2/5 is equal to 4/10. Number two, 9/25. I'll do this one by hand as well. So, 9 / 25. So, we need to extend our division problem with decimal and zero because we can't do 9 / 25 and get whole number. we can't pull group of 25 out of nine. So, now we think of this as 90. How many whole groups of 25 out of 90? Well, three. 3 * 25 is 75. Subtract, we get 15. So, we did not get zero right away like number one. So, we can extend this division problem by putting another zero on the end. zero to the right of decimal doesn't change the value, so we're not changing the problem at all. Now, we can bring that zero down and we have 150 / 25. And we can pull six whole 25s out of 150. 6 * 25 is 150 and we get that clean cut zero, so we do not need to go any further, we are done. And that problem kind of ran into the top problem there, but our answer is 36 hundredths. So, 9/25 is equal to 36/100. Let's take look at number three. Now, number three, if we were to plug in 3 over 3 / 16 into calculator, we would get the following decimal. And it goes to the 10,000ths. So, it's typical to either round decimal to the thousandths or hundredths. So, we're going to round to the thousandths in this video. So, we would take look at what's in the thousandths, look next door. That five says round up. We are closer to 188,000ths. So, our rounded answer would be 188,000ths. So, that rounding step depends on what you're doing with the problem. Maybe you wouldn't round that decimal depending on the situation. And as we'll see with number four and five, we can have decimals that are much longer than just to the 10,000ths place. So, speaking of number four here, we have 1/3 or 1/3. And I'm going to show you this by hand and hopefully you'll notice pattern as start doing this one. So, 1 / 3. So, again, this is just like number one and two where we wrote them out. We can't pull whole three out of that one, so we extend with decimal and zero. Bring that decimal straight up. So, we look at it as 10. So, how many whole threes can we pull out of 10? Well, three. That gets us to nine. 3 * 3 is nine. Subtract, we get one. Remember, we want that clean cut zero to tell us that we are done. So, we need to add another zero, drop it, so we have another 10. How many whole threes out of 10? Well, three. 3 * 3 is nine. And our pattern is going to start here. Subtract, add another zero and drop it, so we have another 10. Three threes out of 10. 3 * 3 is nine. Subtract one and you're probably getting the point here. It's going to go on forever, so it's repeating decimal. So, our answer, this is one we would want to round. And if we round it to the thousandths, we have three there. Look next door, it says stay the same. So, our answer is 333 thousandths. Or if you have repeating decimal, you can write whatever number's repeating and put bar over it and that bar signifies that that digit just repeats. Okay? So, two ways to do that. You can round it off or the bar shows that that digit repeats. So, number five, we actually have an improper fraction. So, this is going to be above one whole. It's greater than whole. so, if you plug 17 over 11 or 17 / 11 in on calculator, you're going to get one .545454 and it's just going to be 54s repeating. So, again, we can round to the thousandths. So, five there. Look Look next door. that says that four says stay the same. So, our rounded answer would be 1.545. So, one and 545,000ths. Or we can use the bar method. forgot to circle my answers for number four there. Just noticed that. Or we can use the bar method. So, one and 54 repeats, so we can put our bar above the 54 to show that that will continually repeat. Number six, 17/20. So, 17 / 20 is going to give us 85/100. So, it cuts off in the hundredths place, so no need to round. that one works out nicely. So, there you have it. There's how you convert fraction to decimal. Divide the numerator by the denominator and then interpret your answer. Do you need to round? Is it repeating decimal? Or maybe it cuts off in the tenths, hundredths, or thousandths place. Thanks so much for watching. Until next time, peace.