Chapter 8 Test Corrections

Question 8: What is the formula for calculating pi?
A pi = radius/circumference B pi = 2 x radius
C pi = diameter/circumference D pi = circumference/diamter

The correct answer is D pi = circumference/diamter

Number of the Day

1. Divide the number by 2
2. Expanded form ex: 123.456 100+ 20+3+0.4+0.05+0.006
3. Write the number in words
4. Round to nearest hundreds ex: 4567.891 6 is higher than 5 so that tells you to go up 4600
5. 9876.543 9 thousands 8 hundreds 7 tens 6 ones . 5 tenths 4 hundredths 3 thousandths
6. Doubled multiply by 2
8. 45 4 is base 5 is exponent together is power
9. 4x4x4x4x4 because you multiply 4, 5 times
10. Cube LxWxH
11. Squared LxW
12. use a calculator and round like # 4 but nearest hundredths
13. 1234.5607 1x2x3x4x5x6x7x0x7= 0
14. Prime number with 2 factors one and itself.
16. Divisible rules
17. 2346.863 one places, tens places 64 2
18. 321.4 2+(-2)= 0
19. 345.6 5-(-3)= 2
20. 4567.892 8/4
21. 8/4
22. mixed whole and proper 9 3/4
23. 9.75
24. 9 3/4 then make a picture of that

http://pi.ytmnd.com/

The Circle Diagram

• This is what we learned in class on thursday!!!!!!!

                                                                            People living in diffrent places 


                                        This is called a Circle Diagram


We learned that a circle graph can help you to know the percentage of
the subject you are talking about. Ex: 31% of the people live in Turkey,
21% of the people live in Iran, 19% of the people live in the USA, 7% of the people live in Chile and 20% live in other places.

We also know that all the percentages  MUST equal up to 100%       


( QUESTION ) if there are 31% out of 100 people living in Turkey how may people are living there?

How to find circumference and area

To find circumference starting with the radius then diameter you have to know these math equations

c=2(pi)r d=2r if the radius is 4 cm what is the circumference?

i will show what i know

r=4 so you times raduis by 2 and it will look like this (4)r X 2=8 the answer is the diameter so now you should know this pi is 3.14 when you are finding the radius you need to multiply it by pi so it will look like
(you need a calculator) 8 X 3.14= 25.1 the real answer is 25.12 but i used the up to tenths

To find circumference starting with the diameter you need to know just one math equation
c=(pi)d
for this you also need a calculator if the diameter is 12 what is the circumference?

To find this you just divide the diameter by pi<======= so it looks like this 12 \ 3.14=3.8

Again I use only the tenths place value

To find area using diameter

to find the area of the circle you basically multiply the diameter by 3 so if the diameter is 8 thern you multiply it by 3 it equals 24

and thats all I know

Circles, Parts of a Circle.

Radius: distance from the center of the circle to the edge, represented by the variable (r). Diameter: the distance across a circle through its center, represented by (d). Relationship between Radius and Diameter: The radius is half of the diameter. The diameter is twice the radius.
Constructing Circles:
1. compass 2. trace a circle 3. string
** contruct a circle with a diameter of 8cm using any method** (What is the raduis?) answer: 4