Skinside out:
Our learning in maths is currently around in the format of an investigation -
Our learning in maths is currently around in the format of an investigation -
The Case of the Missing Bone.
Today in maths we investigated surface area.
Timms Ulrich was an artist, born in Berlin in 1940.
A fascinating character, his motto was 'Remember to forget me'.
Mr Ulrich used to do all sorts of artistic experiments that were quite mathematical.
One day, he took hundreds of little sticky squares of foil that were each one centimetre square and stuck them all over his body, until it was completely covered!
Since each little piece of foil was a square centimetre, he was able to find the total surface area of his body.
He put all the little squares on graph paper in the shape of a large rectangle.
Since there were 18360 of those little bits of sticky foil, he concluded that his surface areas was 18360 square centimetres.
Since there were 18360 of those little bits of sticky foil, he concluded that his surface areas was 18360 square centimetres.
He then displayed the rectangle (about 180cm by 102cm) in art galleries.
In small groups, we made rectangles with newspaper. (Each group had a 'model')
Method:
1. Measure the model's height.
2. Calculate three-fifths of the height.
3. Make a rectangle showing the height measurement by the 3/5 calculation.
(A rectangle with these dimensions (height by 3/5) is claimed to be a good approximation to surface area)
4. How many square centimetres are there in your rectangle.
5. The big challenge now is to put the skin back onto the model!
6. Model and report back your findings.
Here we are at work:
The next part of the challenge:
* Calculate your own surface area by using the rule:
your height by three-fifths of your height.
* Another way to find your surface area is to multiply your height by
your thigh circumference (just one thigh), and
double the answer. So the rule is:
HEIGHT X THIGH CIRCUMFERENCE X 2
*What answer do you get for yourself when you do both these methods?
* Can you write the formula in a different way and still get the same answer?
SHARE YOUR FINDINGS ABOUT YOUR OWN SURFACE AREA -
WHAT IS INTERESTING FOR YOU?
Hi Mrs Rose and Mrs Taylor
ReplyDeleteI find that the two different ways to figure out the surface area give me two different answers.
The second way gave me a smaller number than the first one.
I'm not sure why.
I found out that the two different methods equal different measurements for my surface area but the differences were minor compared to others.
ReplyDeletemy surface area on the method one was 15360 centimetre square and method two was 15040 centimetre square.
the difference between my measurements were 320 centimetres square.
Hi Mrs Rose and Mrs Taylor
ReplyDeleteI find that my two answers where 14229.6cm2 and 12320cm2 and it had a difference of 1909.6cm2 surface area.
I think it was because my thigh is different to other people that are my height.
Hi my surface area was 12226.5 cm2 for the height × three fifths ×height and 10010 cm2 for my height × thigh circumference. So why the big difference?
ReplyDeleteMorning Mrs Rose and Mrs Taylor,
ReplyDeleteI think most people found that the two different mesurements gave two completly different answers.
1.48cm(height)x 28cm(thigh)= 6808 cm squared
2. 3\5 of my hieght(70cm) x height(1.48cm)
Hi
ReplyDeleteFor my skin surface I got two different answers. For my height and thigh circumference I got 13860 cm2 ,and for my height by 3/5 of my
height I got 14229.6 cm2 the differences from 13860 and 14229.6
is 369.6 cm2.
I found out that the two different ways to find out the skin surface area gives me two completely different answers.
ReplyDeleteMy first method was my height(160cm)x my thigh(46cm)x2 = 14720 square centimetres.
My second method was my height(160) x 3/5 of my height(96cm)= 15360 square centimetres.
The difference between my two answers is 640 square centimetres. The first method gave me a larger number then my second method.
Hi Mrs Rose and Mrs Taylor,
ReplyDeleteI found that between my two answers there was a difference of 1,580. I think this is because when i multiplied: thigh times height times 2, it came out much larger because my thighs are bigger
Hi Mrs Taylor and Mrs Rose,
ReplyDeletemy answers were different.
my thigh circumference method was 15,912 cm2
my height times 3 fifths of my height was 15,069.4 cm2
the difference was 842.4
Hello Mrs Taylor & Mrs Rose
ReplyDeleteI found out two different measurements and my second one was bigger first I had done the three fifths of your height which was 96 and the height x thigh x2 was 13904.
I found out my skin area by using this strategy
ReplyDeletethat my height(150cm)x3/5=990cm. Then I went my heightx90=13,500.
And then I calculated my height(150)x my thigh(41cm)x2=12,300
but why so much different between them both
the difference is 1,200 centimetres
Greetings,
ReplyDeleteI found that both the two different ways to figure out the surface area gave me two different answers.
The second way gave me a smaller number than what the first one did.
Hello Mrs Rose and Mrs Taylor,
ReplyDeleteI worked out my skin area using two methods.
Method 1: height x (3/5 of height). 155 x (93) = 14,415
Method 2: height x thigh circumference x2. 155 x 44 x 2 = 13,640
The difference between the two methods = 775
Hi Mrs Rose and Mrs Taylor,
ReplyDeleteI found my surface area using two different methods. One method was my height x three fifths of my height (170cm x 102cm = 17,340 sq.cm). The second method was my height x thigh circumference x 2 (170cm x 50cm x2 = 17,000 sq.cm).
I believe the thigh circumference method would be more accurate for specific individuals.
I learnt that I can get two complete different answers finding the surface area. Method 1 : My height thigh circumference ( 154x34x2=16601.20 cm sq. Method 2: My height x 3/5 of my height or you can go your height x .6 ( 154x.6=92.4)
ReplyDeleteMy difference between my two answers : 16508 Now that is a huge difference. I might have done the method wrong ?