Obviously, IELTS is an English test and the most important thing is that you can use English words and sentences, but sometimes you also need to use numbers. If you are preparing for IELTS, then I hope that you already know English numbers pretty well. You should be familiar with basic counting, able to write down numbers in the thousands, and also somewhat aware of millions and billions.

In this lesson, I’m going to show you how to use numbers for IELTS, with a focus on BIG numbers. First of all, this article was inspired by this video from my YouTube channel:

You can take a look at the video if you want some more active practice.

Small Numbers

First of all, before we begin with the big numbers that will be the focus of our lesson, we should acknowledge that sometimes small numbers appear in IELTS, too.

This is most likely to occur in the IELTS listening test. For this part of the exam, it is quite common to hear phone numbers, addresses, orders, and other instances of small numbers being used. You might, for example, be given a page of information to complete. You would then have to listen and fill in the blanks with the relevant details, including numbers.

Sometimes you will be told to complete an answer USING NO MORE THAN THREE WORDS AND/OR A NUMBER. In such cases, you do have to read the instructions very carefully in order to make sure that you fully understand the instructions.

Big Numbers

how to say very big numbers in english

Here we can see a very large number. Do you know how we could pronounce this? I think that by the end of this lesson, you will be able to say this very easily. (If you want to see the answer, you can skip to the end of the article.)

But first, let’s change this to an easier number. How can we say this?

That’s right. It’s four hundred and twenty-eight. When there are three digits, we take the first number and then say “hundred.” In this case, it is four hundred. The next two numbers can stay as they are. Finally, we add “and” between them.

Hopefully, most of you knew that already. Let’s make this number a little more difficult.

pronouncing big numbers for ielts

So how can we say this number? There are an extra three digits, but it doesn’t change the rules of how we figure it out. It’s three hundred… and… twenty-four thousand… four hundred… and twenty-eight.

You need to think in groups of three. Each three digits is the same: say the first number and then “hundred,” then “and,” then the last two numbers.

This is three hundred and twenty-four… but this is the second group of digits back from the end so it is thousand. Three hundred and twenty-four thousand.

Punctuating Numbers

Well, so far we have had hundred… thousand… and that makes the next three digits MILLIONS. That means this next part is… eight hundred and twenty MILLION. So, altogether, this number is now “eight hundred and twenty million… three hundred… and… twenty-four thousand… four hundred… and twenty-eight.”

If you pay attention to those commas when you are reading numbers, it is actually not so difficult. You just read each part the same, saying “eight hundred… and twenty…” then decide whether it is thousand, million, billion, and so on. You can just leave a gap between the numbers.

Finally, we come to the big number. It can be said as:

thirty-four billion, eight hundred and twenty million, three hundred and twenty-four thousand, four hundred and twenty-eight.

IELTS Writing – Numbers

Fortunately, you won’t have to deal with numbers like that in the IELTS speaking test. However, in the writing test, you may actually come across really big numbers and you need to know how to use them properly.

using billion and trillion for ielts writing task 1

Let’s look briefly at using numbers in IELTS writing because you may have to deal with big numbers in task 1 of the writing test. Look at the above example. It’s a bar chart that measures the amount of electricity ten different countries have produced and used. You can see there are lots of numbers here. When you first look at the numbers, it seems as though they are not so bad. You have these numbers for China: five thousand, three hundred and ninety-eight and five thousand, three hundred and twenty-two.

However, there is a problem. These are actually billions. Can we say, “5,398 billion? 5,322 billion?” No, we don’t, because numbers run in groups of three, a thousand billion is actually a trillion.

You see, a thousand thousand is a million. A thousand million is a billion. A thousand billion is a trillion.

For that reason, 5,398 billion would be more easily said, “five point four billion.” And 5,322 billion would be “five point three billion.”

rounding numbers up or down with billions and trillions

The final thing that you need to know about big numbers is how to round them up or down. This is really, really important for IELTS writing. In that last example, we saw two numbers. They could be written fully with thirteen digits! They’re big numbers, right?! Ok, but we can still count them according to those groups of three digits: hundreds, thousands, millions, billions, and trillions.

Rounding Up and Down

When numbers get really big, you don’t need to say or write every single digit. You can make it shorter by rounding up or down to the nearest of those big numbers, like million or billion. This number is near to four hundred million, so we can round it up. We would now say “five point four trillion.” This next one is much closer to three hundred million, so we can now say “five point three trillion.”

Lastly, we can see how long-form numbers are divided by commas, with one comma every three digits. On the other hand, these shortened versions have periods. I know that this is different in some countries, but in English we need to write it like this.

Avoiding Too Many Numbers

Okay… and one last thing. Please don’t write too many numbers in your IELTS writing task 1 answer. This is an essay and it is about your English use. You are not being tested on numbers. As such, you need to keep those numbers to a minimum. Look at my sample answers here. It has used few numbers and you can also see that I have employed rounding to avoid long numbers. Having too many numbers in your essay makes it seem messy and does not show off your English skills.

Take this example question:

Here is my sample answer to this IELTS writing task 1 bar chart:

Sample Band 9 Answer

The bar chart shows the amount of electricity that was produced and used in ten different countries in 2014. It is clear that China both produced and consumed the most electricity, while South Korea produced and consumed the least.

Of the ten countries, two were runaway leaders in the production and consumption of electricity. First was China, which surpassed five trillion kWh in both categories, and next was the United States, which produced a little over four trillion and used a little less than four trillion kWh. This was about four times the amounts registered by the next country on the list, Russia, which was at about one trillion for production and consumption. Every other country on the list generated and used less than one trillion kWh of electricity.

Every country on the list produced more electricity than they used except for Germany, which used slightly more. They consumed 582.5 billion kWh of electricity, and only generated 526.6 kWh.

Notice how I have changed “thousand billion” into “trillion” and also used rounding in order to avoid long numbers. You can also see how “4 trillion” is now “four trillion” so that I do not have too many numbers. An overabundance of numbers looks messy.


The IELTS exam is a test of your English skills and you do not need to be a maths genius to succeed at it. However, you should have some basic numeracy and be confident using very long numbers such as millions and billions. This will prove helpful for you during the first task of the writing test because tables, line graphs, and bar charts often features this sort of challenge.

You probably won’t need much of this for the speaking test because that sort of question would not arise, but it may be helpful for you just to have the extra confidence. You might be asked about movies and then say something like, “I really enjoyed a movie I watched last night. Apparently, the director spent more than fifty-two million dollars producing the fight scenes, but it was absolutely worth it.”

It is also worth doing some research to see whether the habits of rounding and punctuating are the same in English as your own culture. As I mentioned above, we use commas after each three digits, and periods when we are shortening a number. However, I know that these are pretty much the opposite in Europe.