Sometimes, we round numbers to make them easier to use.
Rounding is finding a simpler number that's close to the number you start with. The results are not exact, but are easier to work with.
In this lesson, we're going to review rounding numbers to the Tens and Hundreds place.
An important thing to know when rounding numbers is the place value of digits in a number.
What digit is in the Tens place?
Yes, it's 7.
The further left the digit, the higher its value.
Now, you're ready to start rounding numbers.
Let's try an example.
Round 413 to the nearest Tens place.
First, find the target digit. This is the digit in the place value we're rounding to.
Our target digit is 1.
When rounding a number, we always look at the digit to the right (👉) of the target digit.
So, let's look at digit in the Ones place.
If the digit to the right of the target digit is less than 5, you round it down to 0.
If the digit to the right of the target digit is 5 or more, you round it up.
Rounding up means we do two things:
1️⃣ Add 1 to the target digit, and
2️⃣ Replace all digits to the right of the target digit with 0.
So let's look at the digit on the right of our target digit: 3.
3 is less than 5, so we round down.
413 rounded to the Tens place is 410. ✅
Round 9,647 to the nearest Tens place.
What's the target digit?
Yes, it's 4 at the Tens place.
So we start by looking one digit to the right (👉). That's the Ones place.
What digit is at the Ones place?
Yes, 7.
Since 7 is more than 5, you need to round up.
1️⃣ We add 1 to the Tens digit.
2️⃣ Then, we replace the Ones digit with 0.
9,647 gets rounded up to the nearest tens is 9,650. Awesome!
Now let's try rounding to a bigger place value. The steps are the same.
What's 10,283 rounded to the nearest Hundreds place?
The target is the Hundreds place.
Our target digit is 2.
So we look one digit to the right of the Hundreds place.
It's the Tens place.
What digit is in the Tens place?
You got it, 8.
Since the digit in the Tens place is 8, we need to round up.
1️⃣ We add 1 to the digit 2 in the Hundreds place.
2️⃣ Then, we replace the digits in Tens and Ones with zeros.
Tip: The digits to the right of the number you round always become 0.
10,283 rounded to the Hundreds is 10,300. ✅
What's 74,816 rounded to the nearest Hundreds place?
What's the target digit?
Yes, it's 8 at the Hundreds place.
So we start by looking one digit to the right (👉). That's the Tens place.
What digit is at the Tens place?
That is right, 1.
Since 1 is less than 5, you need to round down.
So the digit 8 stays the same. Then we replace the digits in Tens and Ones with zeros.
74,816 rounded to the nearest Hundreds place is 74,800. ✅
If the digit to the right of the target place is less than 5, you round down.
Rounding down means:
1️⃣ Replace the digits to the right of the target digit with zeros.
The other digits stay the same.
If the digit one place to the right of the target place is 5 or more, you round up instead.
Rounding up means:
1️⃣ Add 1 to the target digit.
2️⃣ Then replace the digits to the right of the target digit with zeros.
Think you got it? Try the practice.