Lesson video

Hi, I'm Miss Davies.

In this lesson, We're going to learn how to multiply numbers that are in standard form.

When multiplying two numbers in standard form, we can rewrite it like this.

These two calculations are equivalent.

As multiplication, it's commutative and associative.

This means, we can do things in whichever order we choose.

This makes it really simple.

Three times two is six.

10 cubed times 10 to the power of four simplifies to 10 to the power of seven because when we are multiplying two numbers with the same base, we just add the indicis.

Our final answer is six times 10 to the power of seven.

With our next example, we're going to do the same thing.

We've rewritten it as 5.

3 times two times 10 to the power of negative six times 10 to the power of four.

This gives us 10.

6 times 10 to the power of negative two Because we have added the indicis together.

Had to think about what is wrong with this answer.

Well done if you realised, it wasn't in correct standard form.

Correct standard form has the first number between one and 9.

9.

It is now written in correct standard form.

So because 10.

6 was divided by 10 to get to 1.

06, we're going to multiply 10 to the power of negative two by 10.

This means the power has been increased by one.

Here are some questions for you to try.

Pause the video to complete your task and resume once you're finished.

Here are the answers.

In question one, part A and B, the power on the 10 will stay the same.

Whereas in part C, the 9.

24 will stay the same because you're only multiplying by 10.

In this next example, both of the starting numbers in standard form are decimals but this doesn't change the method that we're going to use.

We can rewrite this as 3.

7 times 2.

4 multiplied by 10 cubed times 10 to the power of four.

3.

7 times 2.

4 is 8.

88 and 10 cubed times 10 to the power of four simplifies to 10 to the power of seven.

As this is in correct standard form, it is our final answer.

Here are some questions for you to try.

Pause the video to complete your task and resume once you're finished.

Here are the answers.

Make sure you are adjusting your answers to make sure they are in the correct standard form.

Here are some questions for you to try.

Pause the video to complete your task and resume once you're finished.

Here are the answers.

Remember B squared means B multiplied by B.

Make sure that you're applying the order of operations to these questions as well.

Here are some questions for you to try.

Pause the video to complete your task and resume once you're finished.

Here are the answers.

In part A, you need to multiply 2.

8 times 10 to the power of four by 24 because there's 24 hours in a day.

In part B, you needed to multiply your answer from part A by 365.

That's all for this lesson.

Thanks for watching.