Basic Math Rounding Decimals

Welcome back to Educator.com; this lesson is on rounding decimals.0000

To begin, we need to go over the place values.0007

If I have a number right here, 12,345 and 6679 ten thousandths, each number has a place value.0012

The 1 right here is ten thousands.0030

The 2, the one right before the comma, thousands; this is hundreds, tens, ones.0033

The important part is looking at the numbers after the decimal point.0041

The decimal point is read as AND.0048

6, this first number is not one'ths; it is actually tenths.0051

It starts off as the tenths value with a -TH.0056

The next one would be hundredths, thousandths, ten thousandths; keep this in mind.0061

Make sure you look over this and remember these place values.0070

When we round decimals, the first thing you are going to do is circle...0079

You don't have to circle--but it just makes it easier--the number in the place value that you have to round to.0085

If you look at this example right here, it says this number to the nearest tenth.0094

I know that tenths is the first number after the decimal point.0099

I am going to take that; I am going to circle that number, 5.0103

Look at the number after the circled number; behind; the number behind is a 6.0111

That number behind the circled number, if it is greater than 5,0123

5 or greater, then you add one to the circled number,0127

meaning you are going to round that number up.0132

If it is smaller than 5--4, 3, 2, 1, or 0--then you don't make any changes to that circled number.0135

You keep it as a 5.0143

This circled number is either going to stay a 5.0144

Or it is going to become a 6 if you round up.0147

After you determine that, you are going to rewrite the number, the whole number, the whole thing,0152

but replace all the numbers behind the circled number with 0s.0158

That is the point of rounding; you are going to stop at this number.0164

That is going to be the last number you are going to write.0168

The rest are going to become zeros.0169

This number 6, the number behind the circled number, is greater than 50174

which means I have to take this circled number and round it up.0179

I am going to add 1 to the circled number.0184

This number is going to become a 6; this number is now a 6.0187

I am going to rewrite all the numbers, the whole thing, but replace the last numbers with 0s.0196

My new number, after rounding, it is going to become 1 thousand 2 hundred and 34 and 6 tenths.0203

Then I can put 0s at the end of them.0219

This is my new number, my rounded number.0223

Let's do a few more example; round each.0229

Here is the number; this is read 4 hundred 26 and 93 hundredths.0232

This number right here, 93, you read it as a hundredths because that is the last number that you see there.0241

That is the last place value; this is tenths; this is hundredths.0248

You are going to read this as 93 hundredths.0252

It says to round this to the nearest tenths... sorry, tens.0256

The tens... number the tens value; this is ones; this is tens.0263

I am going to circle that; the number behind it is a 6.0270

It is greater than 5.0275

The 6 value is greater than 5 which means the circled number becomes a 3.0278

I have to round up by adding 1.0285

All the numbers before the 2 stay the same.0291

The numbers behind the 2 are replaced with 0s.0294

Don't forget the decimal though; you still have to have that decimal.0298

This number is before the 2; so 4.0304

The circled number... again remember we were going to round up.0309

That becomes a 3; the 6 becomes a 0; everything else becomes 0s.0313

If I round to the nearest tens, then this number is going to become 430 or 430.00.0323

The next one; round to the nearest tenths; the tenths.0332

Be careful, the tenths is the first number after the decimal point.0339

That is this 0; 0.0343

Then I look at the number right behind it which is a 9.0348

It is greater than 5; my zero rounds up.0350

I do 31 point ...0 becomes a 1; everything else becomes 0.0357

The next few examples; we have this number right here to the nearest hundredths.0372

Tenths, hundredths; circle this number; I look at the number behind it.0377

Is it 5 or greater?--yes it is.0383

That means this 2 rounds up to become a 3.0386

All the numbers before it stay the same, 22.8.0391

Instead of writing the 2, I have to write the 3.0399

The numbers behind it become 0s; that is my answer.0402

The next one, round this to the nearest hundredths again.0408

Hundredths... tenths, hundredths; circle it.0413

The number after it, the number behind it is a 3.0420

That is not 5 or greater; it is smaller than 5 which means my 6 stays the same.0424

If it is smaller than 5, the number behind it, this number right here,0432

if it is smaller than 5, then I don't make any changes to that 6.0435

I don't subtract 1; I just leave it the same.0441

It is either going to be the same; or you are going to add 1 to it.0446

It is 44 and 96 hundredths; and then 00.0452

This number to the nearest tenths.0467

The tenths is again this number right here, the first number after the decimal point.0469

Look at the number behind it; is the number behind it 5 or greater?0474

Yes, it is 5 or greater; it is 5.0478

I have to add 1 to that circled number; this becomes a 1 now.0481

693 and 1 tenths; I can put these as 0s.0487

The next, nearest tens.0498

The difference between this one and this one--tenths, tens; this one has the -TH.0503

That means it is this place value right here after the decimal point.0510

Tens would be this number right here because it is ones and tens.0514

I look at the number right behind it.0521

It is smaller than 5 which means my circled number stays the same.0523

This would be 60 or 69; my 3 changes to a 0, decimal point, 000.0533

Keep in mind, when you have 0s at the end of a number0547

after the decimal point, then I don't have to write them out.0552

Again only the 0s that are at the end of a number and behind the decimal point.0557

In that case, I don't have to write them; you could; you don't have to.0563

If there is a 0 before the decimal point, in front of it,0571

then you have to because 69 we know is different than 690.0575

You have to make sure to have that 0 there.0581

But these 0s, as long as they are at the end of a number,0584

and it is behind the decimal point, then you don't have to write them out.0587

But you could; you could just leave it like this; this is fine.0592

This number to the nearest thousands; no -TH.0600

That means that the thousands is the number right before the first comma.0604

Right in front of the first comma is the thousands.0613

I am going to circle that.0616

The number before it is a 5; it is 5 or greater.0618

That means I have to change this 0 to a 1.0622

I am going to write all the numbers before it--1, 8, 9.0630

Instead of writing the 0, I am going to write the 1; write my commas.0636

Remember all the numbers after the circled number are going to turn into 0s.0643

This was my circled number; that changed to a 1; 0 to 1.0651

It is going to become 000.00.0654

Again because these 0s are at the end of a number,0659

and they are behind the decimal point, I don't have to write them out.0663

But I could if I want; I could just leave it like that.0666

This is the number when you round this to the nearest thousands.0671

Now this one is to the nearest thousandths with a -TH.0678

We know it is behind the decimal point; here is tenths, hundredths, thousandths.0683

I am going to round to that number and circle it.0691

Look at the number behind it; it is a 7.0695

It is 5 or greater; 7 is bigger than 5.0697

That means I change the circled number to a 5; I round up.0701

Again the circled number, it is either going to stay the same if this number behind it is smaller than 5.0707

Or it is going to become 1 bigger if the number behind it is 5 or greater.0715

When I rewrite my number, I am going to write all the numbers in front of it up to my circled number.0721

All the numbers behind it becomes 0s; 5.055; this becomes 0 right there.0727

That is it for this lesson on rounding decimals; thank you for watching Educator.com.0746