Lesson Video: Rounding to the Nearest Hundred Mathematics • Second Year of Primary School

Video Transcript

Rounding to the Nearest Hundred

In this video, we will learn how to round whole numbers to the nearest hundred. When we’re rounding numbers to the nearest hundred, we need to use our knowledge of place value.

This is a three-digit number, 584. The digit we’re rounding is the hundreds digit. The number 584 has five 100s. We know the number 584 comes between 500 and the next hundred, which is 600. To help us round to the nearest hundred, we need to look at the tens digit. 584 has eight 10s. The rule is if the tens digit is five or more, we round up. And if the tens digit is less than five, we round down. The tens digit in the number 584 is an eight. We know that eight is more than five, so we have to round up. 584 rounded to the nearest hundred is 600.

If a class sold 147 cupcakes in a cake sale, how many cakes did they sell to the nearest hundred? We have to round number 147 to the nearest hundred. The one in the number 147 is worth 100. So we know the number 147 comes after 100 and before 200. The number 147 is between 100 and 200. To help us decide if the number 147 is nearest to 100 or 200, we need to look to the tens digit.

There are four 10s in 147. We know that four is less than five. And if the tens digit is less than five, we round down. 147 rounded to the nearest hundred is 100. So, when we’re rounding to the nearest hundred, we need to look to the tens digit. If the tens digit is five or more, we round up. And if the tens digit is less than five, we round down. Let’s practice rounding whole numbers to the nearest hundred with some questions.

Michael has 236 marbles and Noah has 250 marbles. How many marbles does Michael have, rounded to the nearest hundred? How many marbles does Noah have, rounded to the nearest hundred?

Michael and Noah are collecting marbles. Michael has 236, and Noah has 250. In the first part of the question, we need to round the number of marbles that Michael has to the nearest hundred. Michael has 236 marbles, so we need to round 236 to the nearest hundred. 236 has two 100s. 236 is between 200 and 300. To help us work out which is the nearest hundred, we need to look to the tens digit. 236 has three 10s. Three is less than five. And if the tens digit is less than five, we have to round down. 236 rounded to the nearest hundred is 200. The number of marbles Michael has, rounded to the nearest hundred, is 200.

Now we need to round the number of marbles that Noah has to the nearest hundred. Noah has 250 marbles. We know that when we’re rounding to the nearest hundred, we need to look to the tens digit. And if the tens digit is five or more, we have to round up. The tens digit in 250 is a five, so we have to round up. 250 rounded to the nearest hundred is 300. The number of marbles Noah has, rounded to the nearest hundred, is 300. Michael has 236 marbles. 236 rounded to the nearest hundred is 200. Noah has 250 marbles. 250 rounded to the nearest hundred is 300.

William has 456 marbles. We want to round this number to the nearest hundred. Complete: The number 456 is between what and what. How many marbles does William have to the nearest hundred?

We know that William has 456 marbles, and we need to round this number to the nearest hundred. In the first part of the question, we need to complete the missing numbers. In other words, which two hundreds is the number 456 between? The number 456 has four 100s. It comes after 400 and before 500.

To find out which hundred 456 is nearest to, we need to look to the tens digit. 456 has five 10s. If the tens digit is five or more, we have to round up. So we have to round up to 500. The number 456 is between 400 and 500. And the number of marbles William has, rounded to the nearest hundred, is 500. 456 rounded to the nearest hundred is 500.

A farm contains 254 cows. Round the number of cows in the farm to the nearest hundred.

We know that a farm has 254 cows, and we have to round the number of cows to the nearest hundred. When we’re rounding to the nearest hundred, we need to look to the tens digit. If the tens digit is five or more, then we have to round up. The tens digit in the number 254 is a five, so we have to round 254 up. We know the number 254 has two 100s. It comes between 200 and 300. So 254 rounded to the nearest hundred is 300. If a farm contains 254 cows, the number of cows in the farm, to the nearest hundred, is 300.

Which of the following numbers rounds to 100 when rounded to the nearest hundred? 161, 176, 156, or 78.

In this question, we have to work out which of the four numbers we’re given rounds to 100 if we round the numbers to the nearest hundred. Let’s start with the number 161. When we’re rounding to the nearest hundred, we need to look to the tens digit. If the tens digit is worth five or more, we have to round up. We know that six is more than five, so we need to round up. The number 161 has one 100. It comes between the hundreds 100 and 200. We need to round up to 200 because 161 has six 10s, and if the tens digit is five or more, we have to round up. 161 rounded to the nearest hundred is 200.

We’re looking for numbers, when we round them, which round to 100. The number 176 has seven 10s. Seven is more than five. So again, we need to round this number up. 176 rounded to the nearest hundred is 200. The number 156 has five 10s, and we know if the tens digit is five or more, we have to round up. So 156 rounded to the nearest hundred is also 200.

The number 78 has no hundreds. It comes between the numbers zero and 100 on the number line. When we’re rounding to the nearest hundred, we need to look to the tens digit which, in this case, is a seven. And we also know if the tens digit is five or more, we need to round up. So 78 rounded to the nearest hundred is 100. The number which rounds to 100 when rounded to the nearest hundred is 78.

What have we learned in this video? We’ve learned how to round whole numbers to the nearest hundred by identifying the two hundreds numbers a number is between and by looking at the value of the tens digit. We’ve also learned that when the tens digit is less than five, we round down. And if it’s five or more, we round up.