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Hi everyone, I'm Ms. Mitchell.

Today in math, we're going to be drawing lines with specified lengths.

So I'm going to draw a line that is 15 centimetres long.

So to do this, I have my pen or pencil, and my ruler.

The first thing I'm going to do is carefully hold my ruler.

And I'm going to see where the zero is, which is here.

And then I'm going to look for the number 15, which is here, as this is the number I need to draw, 15 centimetres.

I then put my pen carefully on zero, and I draw, stopping carefully on where the number 15 is.

I'm then going to take my pen away, and then I'm just going to measure it and check.

So my zero is at the beginning of the line and the 15 is at the end of the line.

That is a line that is 15 centimetres long.

I would like to draw another line, but this time, the line is going to be four centimetres longer than 15 centimetres.

So I'm looking for a line that is four centimetres longer than 15 centimetres.

So how long is my line going to be if it's four centimetres longer than 15? So to work that out, I would do 15 plus four, which is equal to 19.

So if you could do it with me, have your pencil and paper ready, put your ruler on the paper and look for where the number zero is and just draw a little dot there.

Then without moving the ruler, draw along the ruler up until the number 19 and look really carefully, and stop there.

Take the ruler away and then remeasure the line to check that the line you have drawn is 19 centimetres, Making sure the beginning of your line starts at the number zero, not at the beginning of the ruler and not at the number one, at the zero, and that the end of your line ends exactly on the number 19.

Could you please pause the video to have your go? Let's try one more.

I would like to draw another line that is three centimetres longer than 15 centimetres.

I would like to draw another line that is three centimetres longer than 15 centimetres.

How long is my line going to be? Pause the video to work this out now.

So to work this out, my equation would be 15 plus three is equal to the unknown, and I know that 15 plus three is equal to 18.

So could you pause the video and have a go at drawing a line that is 18 centimetres long? If you're not sure, ask a parent or carer to check your work after.

I would like to draw another line that is three centimetres shorter than 15 centimetres.

I would like to draw another line that is three centimetres shorter than 15 centimetres.

Pause the video to see if you can work out how long my line's going to be.

So to work this out, I would do 15 centimetres, take away three centimetres, which is equal to the unknown.

I can then solve this equation, and I know that 15 takeaway three is equal to 12.

Could you pause the video and draw a line that is 12 centimetres long? Well done, you're ready for your independent task.

Could you solve these questions and work out how long the mystery line is going to be? As well as solving the problem, can you draw the line too? Make sure you've checked your answers, and if you can, ask a parent or career to check your work too.

Pause the video now.

And here are the answers.

Pause the video to check your answers are the same as mine.

If you have drawn the line too, if you can ask a parent or carer to check your work.

Well done for completing the lesson.

If you'd like to share your work with Oak National, please ask your parent or carer to share your work on Twitter, tagging @OakNational and hashtag #LearnWithOak.

You've worked really hard today, so well done.

Now let's see what you can remember by completing the quiz.

See you later, bye!.