### Video Transcript

The picture shows a man standing next to a house. The house and the man are drawn in the same scale, and the man is of average height. Part a) Write down an estimate for the actual height of the man in metres. Part b) Work out an estimate for the actual height of the house in metres.

So first of all, we want to find an estimate for the actual height of the man in metres. Well, if you think about height of man, then the actual average height of a man is approximately 1.8 metres because it is actually about 1.75 metres. I find that there’s kind of certain ways you can help to remember that: one because it’s between one and a half and two metres approximately because if you put 1.75 or 1.8 metres, that will get you the mark.

Another way you can actually think of to help you remember is actually if you think that two metres — so I always remember that two metres is approximately equal to six feet birches — then some people still think of height in feet and inches. Well, if two metres is equal to six feet birches, well, this is quite tall for a man where none of people are six feet birches tall. However, if you’re looking for a man of an average height, then to a bit less than this and we remember we can have 1.8 metres.

Okay, great, so we have got an estimate for the actual height of a man in metres. So now, for part b, what we need to do is work out an estimate for the actual height of the house in metres. So now, what you can do actually on the question paper you’ve got is actually measure the height of the man and then measure the height of the house because it tells us in the question that the man and the house are actually drawn in the same scale. So therefore, we can actually see how many times bigger the house is than the man.

So when I’ve done that, I can see that actually the house is 4.5 times bigger than the man. So what we could say is actually 4.5 multiplied by 1.8 will give us the actual height of the house in metres. However, as it’s actually asking for an estimate, what we’re gonna do is actually round the estimate for the height of the man in metres to one significant figure.

So then, we get 4.5 multiplied by two. And we get this because actually we round the 1.8 up to two because to one significant figure, we’ve got one. And then, the number after it is eight because it’s a five or above, we round the one to a two. And this is gonna give us an answer of nine metres. We get this because well one way of working out would be four multiplied by two equals eight, 0.5 or a half multiplied by two equals one, eight plus one equals nine.

So therefore, we can say that the estimate for the actual height of the man in metres is 1.8 metres and the estimate for the actual height of the house in metres is nine metres.