Math Notes

Math Notes
For April 27, 2009
Grade 7
MCAS Review
Quiz 1

You do not need to show your work on the MCAS unless they ask for it in the short answer section


What % is 14/25?

To find the percent you can divide 14 by 25 or you can multiply the denominator by 4 to get 100. You must then multiply the numerator by 4. Your new numerator will be your answer when expressed as tenths, in other words, move the decimal to the left 2 spaces



If n=-5, what is the value of –(n+3)


Substitute the n for -5 so it be comes:
-(-5+3)
Now use PEMDAS to complete the equation
(figure your operations in the following order: parenthesis, ellipses, multiplication, division, addition, subtraction)
So, -5+3=-2
Now you have -(-2)
The negative outside the parenthesis is considered to be a -1
-1(-2)=2



MCAS Review from 2008
Session 1

Question 9

Below the x axis means under the horizontal line
Reflection-means “to flip it over”
A slide- means to move it over
Don’t get tricked by the grid, check to see where 0 is. If a point is 2 on the y axis, it will be -2 on the y axis for the reflection even if there isn’t a grid line.
Remember (x,y)
(the x axis point is always listed first, then the y)




In the 4 quadrants:

quadrant I is (+x,+y)-this is the upper right quadrant
quadrant II is (-x,+y)-this is the upper left quadrant



#12 Absolute value

means the distance from 0. When adding or subtracting absolute value the answer will always be positive for instance 4- -9= 5
It’s not negative 5 because we are only concerned with the distance from 0.

#13 Scientific notation


The exponent tells you the number of zeros you should have, so 10 to the first power=10, 10 to the 5th power= 10,000

#14 Probability

Write the number of favorable outcomes over the number of total possible outcomes
There are 6 total possible combonations. She wants a green ruler with a black or purple ruler. What is the probability she’ll get it?
2 out of 6 or 2/6




Homework:



Study for quiz page 307-309 except 15 and 16
Math’s Mate due Wed Term 2 sheet 6





Math Notes
For April 27, 2009
Grade 8
MCAS Review of 2008 test
Session 1
Quiz
1. What is true about the slope of parallel lines?


2. Solve. 1/3x +2 =12







MCAS review
Session 1 from 2008 MCAS
#9 Graphing and Patterns







The slope is the same.
Perpendicular lines will have have an inverse or opposite slope.

Isolate x by taking the reciprocal of 1/3, which is 3/1, or just 3, and multiply it all of the terms on both sides.
This cancels out the 1/3 on the left side of the equation and creates
x + 2 x 3 = 12 x 3
on the right side of the equation.
x + 6= 36
x=30

a.In looking at the table you can see that the perimeter is always the number of triangles + 2





10. Exponents



11. Graphing
12. Algebra
y/-7=21

13. Reading Graphs/Tables


14. Division



15. Algebra
HW: study for quiz pp. 184-187
b. If you call the number of triangles n and the outer perimeter p, you could say
p=n + 2

c. This will be a straight line with a continuous slope
When multiplying numbers with exponents, add the exponents.
Answer: 4 to the eleventh power

Answer: 3

You can cross multiply to help solve.
Answer: Game 4
It has the least difference between the winning and losing team
Division is the reverse of multiplication, therefore multiplying something by a number is the same as dividing it by the reciprocal. Remember a neg. times a neg =

30-60-90 and 45-45-90 Triangles

In a 30-60-90 triangle:

• The side opposite the 30 degree angle is equal to half the hypotenuse.
• The hypotenuse is equal to twice the side opposite the 30 degree angle.
• The side opposite the 60 degree angle times the square root of 3.

In a 45-45-90 triangle:

• The hypotenuse is equal to the side opposite 45 degree angle times the square root of 2.
• The side opposite the 45 degree angle is equal to the number that is multiplied times the square root of 2 for the hypotenuse length.

7th Grade - 3/24

Math Notes-March 24th Grade 7
Investigation 7
7.1 page 7 Finding diameter Finding circumference	is answeris is the length across the center of the circle you you can measure a quarter of the circumference with string and then multiply this number by 4 (because there are 4 total groups) dfjdj
relationship between diameter and circumference	If you plot this on a graph, you’ll see that circumference is about three times as much as the diameter. Mathematicians figured out that there was a pattern to this. It was slightly more than 3 times the diameter. They call it pi. Pi is approximately equal to 3.14 (the decimal actually continues infinitely because it is an irrational number but we round it to 3.14 to make it easier to work with).
Pi »3.14» 22» 7	3.14 or it can be expressed as the fraction 22 over 7
Homestudy	#’s 1-5 on page 76. Find all measurements except area. Use 3.14 for pi

8th Grade - 3/23

Math Notes-March 23rd
Grade 8
Investigation
Homestudy


Math’s Mate due Tuesday
3.1 on p. 28 You may use key to help find areas of tilted squares. Otherwise, use strategy reviewed in class today (inscribing a tilted square in an upright square, finding negative space, continued. All computing is to be shown.

Make-up tests were given to some students
Went over check-up “test”-you will need this info for tonight’s homework as well
***save this to help you study for your unit test!

Note the areas you need to work on and come on Thursday for extra help in homework club. Ask Marc for assistance

To find the length of a tilted line segment, make a square that will go outside the square. Use slope to make the right lines.
step 2 Trace a square around the tilted square you have made.
step 3 Make a rectangle to turn one of the line segments into a triangle.
step 4 Find the area and divide by 2. This gives you the area of the negative space.
step 5 Find the area of the larger square and subtract the area of the negative space from this number.
step 6 The answer to the problem is the square root of your answer from step 5.

Investigation 3
page 27 hypotenuse- the longest side of a right triangle
conjecture-similar to a hypothesis. They are the opinions given after an analysis of the data has been completed.

You need your key to complete this.
***for each triangle, you will draw 3 adjacent squares like those shown on page 27

7th Grade - 3/23

Math Notes-Grade 7
Investigation 7
7.1 page 70 How can we find the inches per dollar for the medium?	Jane-We are going to find the cost per square inch. How are we going to do it? How about how much we get for a dollar? How do we find out how many inches we get for a dollar? How could we regroup the inches into 6 dollar bills. Taylor-We could divide 63.6 in. squared by 6. Answer: 10.6 square inches. For the medium pizza, the answer is answeris dfjdj
Homestudy Begun in class What do you need to begin?	Complete the assignment on Lab sheet 7.4 Follow the directions in the margin. Read directions. What is a strategy for finding the circumference when part of the circle is missing? student-use a compass student-draw on it Jane-Remember I said don’t draw on it. student-use a quarter of it and multiply by 4 Jane-you could even use a half student-Are we allowed to use formulas? Jane-No formulas are allowed. You need a table. You need an object.