Tutor.com Real Numbers Session

Aug. 6, 2013

Session Transcript - Math - Algebra, 8/5/2013 5:12PM - Tutor.comSession Date: 8/5/2013 5:12PM
Length: 26.2 minute(s)
Subject: Math - Algebra

System Message
[00:00:00] *** Please note: All sessions are recorded for quality control. ***

Guest (Customer)
[00:00:00] express 21 1/4% as a fraction in simplest form

Kevin T (Tutor)
[00:00:06] Welcome to Tutor.com ! Let's get started.

Guest (Customer)
[00:00:14] ok

Kevin T (Tutor)
[00:00:28] hi

Guest (Customer)
[00:00:34] hi

Kevin T (Tutor)
[00:00:39] any idea how to start?

Guest (Customer)
[00:00:44] no

Kevin T (Tutor)
[00:01:06] that's fine, let's work through this
[00:01:12] there's a percent sign after that, right?

Guest (Customer)
[00:01:12] ok
[00:01:19] yea

Kevin T (Tutor)
[00:01:59] okay, so 21 1/4%
[00:02:06] What do you know about percent values?
[00:02:09] what does it mean to you?

Guest (Customer)
[00:02:36] i think it is how much the percent is

Kevin T (Tutor)
[00:04:11] okay, let me give you an example.. if there is a 25% chance of winning a drawing
[00:04:32] that means you would win 25 times
[00:04:43] if you entered 100 times
[00:05:01] on average, at least

Guest (Customer)
[00:05:08] yes ok

Kevin T (Tutor)
[00:05:20] so what % means is parts per 100
[00:05:38] 100 is the whole

Guest (Customer)
[00:05:40] ok

Kevin T (Tutor)
[00:05:43] and you're taking bits of that
[00:05:51] in this case, 21 1/4 parts of that 100

Guest (Customer)
[00:05:55] ok

Kevin T (Tutor)
[00:06:08] so in order to express as a fraction
[00:06:21] do you have any idea what operation we need to do between the 21 1/4 and 100?

Guest (Customer)
[00:06:39] no

Kevin T (Tutor)
[00:07:19] which operation, out of addition, multiplication, division, subtraction, deals with parts of a whole?
[00:07:29] yes, that's right!
[00:07:38] You divide it by 10
[00:07:43] 100*

Guest (Customer)
[00:07:43] idk

Kevin T (Tutor)
[00:07:51] no, you're on the right track

Guest (Customer)
[00:07:52] ok

Kevin T (Tutor)
[00:08:32] so from here, all we need to do is some arithmetic to divide these two numbers.

Guest (Customer)
[00:08:51] do i make 21 1/4 a decimal

Kevin T (Tutor)
[00:09:14] we need to keep it a fraction because our final answer is going to be a fraction.
[00:09:17] however
[00:09:31] as a mixed fraction, it's difficult to do the division
[00:09:39] we need to convert it to an improper fraction.
[00:09:48] are you familiar with improper fractions?

Guest (Customer)
[00:10:06] yes

Kevin T (Tutor)
[00:10:35] awesome. if you can, try converting the 21 1/4 to an improper fraction.

Guest (Customer)
[00:11:12] ok it is 85/4

Kevin T (Tutor)
[00:11:26] correct
[00:11:47] so that's what we have now
[00:11:58] can you do the rest of the arithmetic?

Guest (Customer)
[00:12:13] how

Kevin T (Tutor)
[00:12:39] we are dividing the 85/4 by 100

Guest (Customer)
[00:12:53] ok

Kevin T (Tutor)
[00:13:04] when you divide with fractions, what are you really doing?
[00:13:09] hint: has to do with multiplication

Guest (Customer)
[00:13:49] ummmmmm...
[00:14:25] oh k

Kevin T (Tutor)
[00:14:29] okay see that 85/4 divided by 100/1
[00:14:49] the trick is, you can change the divide sign to multiplication
[00:14:57] and flip the second number

Guest (Customer)
[00:15:01] ya i know that

Kevin T (Tutor)
[00:15:51] so give the rest of the calculation a shot
[00:16:47] you multiplied the two numbers, but didn't flip the second number

Guest (Customer)
[00:17:10] is this right

Kevin T (Tutor)
[00:17:35] you left out the step where you flip the 100/1

Guest (Customer)
[00:18:10] ohhh
[00:18:55] is this it

Kevin T (Tutor)
[00:19:19] yes, that's correct.
[00:19:25] now we just need to reduce it to simplest form
[00:20:11] do you know how we can do that?

Guest (Customer)
[00:20:31] yes

Kevin T (Tutor)
[00:21:07] great! let me know when you have an answer

Guest (Customer)
[00:21:15] k\
[00:23:00] 17/80

Kevin T (Tutor)
[00:23:16] that's correct!
[00:23:33] to recap, percent values are always parts of 100

Guest (Customer)
[00:23:38] k thanks

Kevin T (Tutor)
[00:23:55] so to convert a percent value, what do you divide by?
[00:24:36] and this works to convert to both fractions and decimals.

Guest (Customer)
[00:25:35] k thanks

Kevin T (Tutor)
[00:25:54] Thanks for using Tutor.com.Â Please fill out the survey as you leave so we can learn how we can better help you in the future!Â
[00:26:02] Bye! :)