Question Video: Multiplying One-Digit Numbers by Multiples of Ten | Nagwa Question Video: Multiplying One-Digit Numbers by Multiples of Ten | Nagwa

Question Video: Multiplying One-Digit Numbers by Multiples of Ten Mathematics • Third Year of Primary School

Calculate 2 × 3. Use the answer to the previous question to help you calculate 2 × 30. From the answers to the previous questions, which of the following is equal to 2 × 30? [A] 2 × 3 [B] 2 × 3 × 0 [C] 2 × 3 × 2 [D] 2 × 3 × 10 [E] 6 + 10

03:41

Video Transcript

Calculate two times three. Use the answer to the previous question to help you calculate two times 30. From the answers to the previous questions, which of the following is equal to two times 30? Two times three, two times three times zero, two times three times two, two times three times 10, or six plus 10.

This question has three steps to it. And to start with, you might look at it and think to yourself, what have all these steps got to do with each other? They’re asking three different things, aren’t they? Well, yes, each part does ask us to do something different, but they’re all related. And hopefully, by the end of this question, you’ll be able to see how they’re linked and importantly how this very first, quite easy fact can help us work out something much harder.

So to begin with, we’re asked to calculate two times three. Hopefully, we don’t have to think too much about this, do we? Two threes are six. On to the next part. We’re now asked to use the answer to the previous question, so that’s the number six, to help us calculate two times 30. How can we use the answer to that simple multiplication to find the answer to this one, which is a lot harder? Well, let’s take a moment to look at this calculation. We’re being asked to multiply a single-digit number, two, by a multiple of 10, 30. We know the number 30 is a multiple of 10 because it’s a number in the 10 times table. It’s worth three 10s. And knowing this is going to help us.

Two times 30 is the same as saying two times three 10s. So how many tens is that? Maybe now you can see how the answer to the previous question can help us. If two times three is six, then two times three 10s is six 10s. And what are six 10s worth? We just need to multiply our first answer by 10. Six times 10 equals 60. Our second answer is 10 times as large as the first one.

In the third part of this question, we’re asked to use what we’ve done previously in those first two calculations to help us find a calculation that’s equal to two times 30. So let’s go back right to the start and talk through what we’ve done. We wanted to find two times 30. We know that 30 is worth three 10s. So first, we found two times three. This gave us the number of tens in our answer. And to find the value of our answer, we then multiplied this by 10. Can you see which one of the calculations is the same as this? Let’s write it out as we say it.

First, we found the value of two times three. As we’ve just said, this gave us the number of 10s in our answer. And to find the value of our tens in the answer to our question, we need to multiply this by 10. Two times three times 10 is the same as two times 30, and we can see why. The number 30 is simply being split up into three times 10.

In this question, we’ve found how we could use a fact we already know to help us multiply a one-digit number by a multiple of 10. If we know two times three, we can use this to help us find two times 30 because we know our answer will be 10 times greater. Two times three equals six. And so we know two times 30 must be equal to 60, which is the same as two times three times 10.

Join Nagwa Classes

Attend live sessions on Nagwa Classes to boost your learning with guidance and advice from an expert teacher!

  • Interactive Sessions
  • Chat & Messaging
  • Realistic Exam Questions

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy