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### Course: 7th grade (Illustrative Mathematics)>Unit 1

Lesson 7: Lesson 9: Creating scale drawings

# Creating scale drawings

Sal uses real world contexts to create scale drawings on a grid.

## Want to join the conversation?

• I mute it, listen to music, and look at the subtitles.
• I feel like I would get grounded for doing that TvT
• "this is making my eyes hurt"

this is making my brain hurt
• Maybe not for me.
• Im literaly going to throw my chromebook
• I sha'll be here to virtually catch it.
• I really do not get it because my problem was way more different than this guys and I do not understand
• same its stressing me out some much i cried a little
• this doesn't help at all this is so different than my actual question
• Sal is showing you a basic question because he wants you to get the basic idea and use it on other problems.
• I don't think he explains enough
• true.He does not explain enough
• How do i do this I dont get it
• you must bring the two types of units beside each other one is 'units' and the other is 'mm' then he tells you that 1 'unit' is equal to 1/2 'mm' then he says that the chip is 9 'mm' so you divide 9/0.5=18, then you multiply 1*18=18

Hope this helps
• I was confused about a problem, so I came to watch this video that Khan recommended to me, and the problem in the video is LITERALLY the EXACT SAME PROBLEM that I'm on! [;-;]
• why is my question like converting 18 to 60 and his is 1/2 to nine?
• You don't always get the same question as him or it would be free cause you would already know the answer
• It doesn't make sense the questions I get are different than what he explained.

## Video transcript

- [Instructor] Sue is a software engineer. She wants to create a large scale drawing of a processor inside a cell phone. The processor is a square chip, nine millimeters on each side. Draw the processor such that one unit on the grid below represents one half of a millimeter. All right, so let's just think about these two worlds. You have the drawing, and you have the chip in the real world. The drawing, we're thinking in terms of these units here on this graph paper, so units. And the chip, we're thinking in terms of millimeters. And so we can set up a table here. And they tell us draw it such that one unit represents half a millimeter. So one unit would represent one half of a millimeter. They tell us that the processor is nine millimeters on each side. So that is how many times as many millimeters? Well, to go from one half to nine, you have to multiply by 18. So that's going to be 18 times as many units as well. So if I want to do a scale drawing right over here, it's going to be a square. It's a square chip. And since the scale is one unit, it represents half a millimeter. 18 units would represent nine millimeters, and so I would want to do 18 units on a side. So one, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18. So that would be the left side of the chip. Let me just see if I can draw a straight line there, just like that. And then it would also be 18 wide, 18 units wide, representing nine millimeters in the real world. One, two, three, four, five, six, seven, eight, nine, 10, 11, 12, 13, 14, 15, 16, 17, 18. This is making my eyes hurt. All right, so just like that, and then I could draw the other parts of it. It would be like that, and then I would just go straight down like that. And there you have it, I have drawn a scale drawing of our processor, and we are all done.