View source for Plane Figures: Horizontal line - curved or straight?

=== Age  ===

6-9.<br>

=== Materials  ===

*A globe
*Frame of smallest circle inset
*Knitting needle<br>

=== Preparation  ===

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=== Presentation  ===

#Invite the child to identify their hometown on the globe.
#Place the inset frame on the globe so that the town coincides with the center of the circle. 
#This curve (the rim of the frame) represents the horizon for everyone living here in and around the town. 
#Because we are standing outside the earth we see the entire horizon as a circle, instead of as an arc-part of the circumference.
#With the chalk mark a point on the floor. 
#Draw a circle around this center point. 
#Invite the child to stand at the center. 
#What do you see? Without turning the child can only see an arc, a part of the circumference.
#Reinforce the facts that in these demonstrations the child is much bigger than the circle on the globe or on the floor, when in reality it is the reverse. 
#The child is a tiny, tiny point in relation to the earth which is huge. 
#The curvature of that arc would be so slight that you would only be able to see a straight line.
#With the knitting needle, hold it so that it forms an arc on a horizontal plane. 
#Invite the child to identify what he sees as he lowers his body..... a curved line.... a curved line... a straight line. 
#At eye level this curved line looks like a straight line.<br>

=== Control Of Error  ===

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=== Points Of Interest  ===

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=== Purpose  ===

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=== Variation  ===

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=== Links  ===

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=== Handouts/Attachments  ===

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[[Category:Mathematics]] [[Category:Mathematics_6-9]]