Multiplication Table

1
Multiplication Table
2
Geometry

• Lesson 6-6
• Pg. 337 - 340

• Story Problems involving Circumference

3

• If the diameter of the earth is 8000 miles, find
  the average speed in miles per hour Phileas Fogg
  needs to circumnavigate the earth about the
  equator in 80 days.

• Remember
• D r?t
• D distance
• r rate (speed)
• T time

• Also
• r D/t
• t D/r

4

• 1st To find the speed we need to know the
  distance and time.
• C ?d
• C ? ?(8000)
• C ? (3.14)(8000)
• C ? 25,120 miles
• So, Phileas must travel 25,120 miles in 80 days.

5

• 2nd Since Phileas is traveling in miles per
  hour, we must change the number of days to the
  number of hours.
• 80 days times 24 hours to a day
• 1920 hours
• Now we have enough information to put into a
  formula.
• r d/t
• r ? 25,120 mi./ 1920 hrs ? 13mi/hr

6

• If the front tire of a motorcycle has a diameter
  of 50 cm (half a meter), how many revolutions
  will it make if it is pushed 1 km to the nearest
  gas station? In other words, how many
  circumferences of the circle are there in 1000
  meters?
• 1st We need to find the circumference of the
  wheel. How do we do that?

7

• We now need to find the circumference of the
  tire.
• C d?
• C 50(3.14)
• C 157 cm 1.57 m
• Now how can we translate what we know into number
  of revolutions of the wheel?

8

• Since we know how far we are going to travel,
  1000 m, and how far each revolution of the wheel
  will take us, 1.57m, then dividing 1000 by 1.57
  should give us the number of revolutions of the
  wheel.
• 1000/1.57 ?637 revolutions
• Pg. 339 -340 1-6 all, 11,13- 15 all.