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Staging content lifeboat
Course: Staging content lifeboat > Unit 14
Lesson 45: Decimals in expanded formConvert decimal from expanded form to standard form
Learn to write (4x1,000,000)+(3x1000)+(67x1/1000) in standard form. Created by Sal Khan.
Want to join the conversation?
- Why are decimals so important?(really why)(15 votes)
- Decimals are so important because money is basically decimals.
one dollar and fifty five cents = 1.55(1 vote)
- Why do you need to now how to write stuff in expanded form and rewrite it in
decimals? (Like WHY!)(2 votes) - Why did he have to put parenthesis? Could you not do it without parenthesis?(2 votes)
- The parenthesis show what to do first. You do the parenthesis first, then the exponents, then multiply and divide, and finally add and subtract. Remember to always go from left to right.(1 vote)
- What is an easy way convert decimal in expanded form(2 votes)
- Sometimes....You just use big words and it confuses me. Who agrees...?(2 votes)
- I agree with you. If you don’t know a word I suggest using the Merriam Webster Online Dictionary.(1 vote)
- Let's say I'm doing a question like 10 x 5 divided by 10 x 6. Does it matter where I put the parentheses?(1 vote)
- Yes it does very much because if you put the parentheses on the wrong side of the equation then it will mess the whole thing up(2 votes)
- sal just wanted to know that how to do decimal place value send a link if you have a video(1 vote)
- Not Sal here, but here's a video on place value, specifically for decimals: https://www.khanacademy.org/math/cc-fifth-grade-math/cc-5th-place-value-decimals-top/5th-cc-decimals-place-val/v/expanding-out-a-decimal-by-place-value(2 votes)
- where do you find the financial literacy video(1 vote)
- When the thousandths place is over ten does it go into the next place value(1 vote)
- yes it should go to the hundredths place, example: 1 one 3 tenths 4 hundredths and 13 thousands so it is actually 1 one 3 tenths 5 hundredths and 3 thousands 1.353(2 votes)
- what if u have more then one after the decimals(1 vote)
- that means that you have a very big numbers(1 vote)
Video transcript
I want to write this
expression here as a decimal. And the first question
that might pop in your head is do I multiply 4 times 1,000,
then add 3, then multiply 1,000, then add 67, then
multiply by 1 over 1,000? Or do I do the
multiplication first? To answer that
question, we just have to remind ourselves about
order of operations. Order of operations, if you
have a bunch of multiplication and addition in a
row like this, you will do the
multiplication first. Let me put some parentheses
here to remind us of that. So let's figure out what
each of these expressions in the parentheses
actually represent. What's 4 times 1 million? Well, that's 4 million. What's 3 times 1,000? Well that's 3,000. What is 67 times 1 thousandth? And there's a bunch of ways
of thinking about this. Actually, let me write
them all over here. Well, I'll do the most
obvious one right over here. 67 times 1 thousandth
is 67 thousandths. And we can represent this
literally as 67/1000. Or we could represent this as
60 over 1,000 plus 7 over 1,000. And what's 60 over 1,000? Well, 60 over 1,000
is 6 hundredths. So let me put that
in a different color. 6 hundredths, 7 thousandths. So you could view this
is 67 thousandths. Or you could view this is 6
hundredths and 7 thousandths. Either way, let's add all
of these things together. So we have 4 million. So the 4 in the millions place
literally represents 4 million. Then we have no
hundred thousands. We have no ten thousands. But then we have 3,000. So the 3 is in the
thousands place. Let me put a comma here, so
we can keep track of things. And then we have no hundreds. We have no tens. We have no ones. We don't even have any tenths. But we do have some hundredths. We have 6 hundredths. And then we have
some thousandths. We have 7 thousandths. So we put that 7 in
the thousandths place. So we could read this 4 million,
3 thousand, 6 hundredths and 7 thousandths. Or we could read it as
4 million, 3 thousand, and 67 thousandths.