Grade 8 Math Portfolio

Trick

+ and + = +

+ and - = -

- and - = +

- and + = -

This trick is used when doing addition, subtraction, multiplication and division.

Thank you!

Grade 8 Mathematics

Example: (-3) + (-4)

= -7

The two red signs are what you need to look at when doing this trick.

Learning Goals

Since a positive and a negative equals a negative, you need to go left in a number line.

General Goal: To solve for unknown variables by balancing the equation.

4

Geeky Goal: To develop your own equations based on word problems in order to solve it.

What is a Circle?

A circle is round. It has a center and if divided has all equal sides.

Examples- Integers

Tutorial For Order Of Operations

1. +8 + (-3) = +5

Follow B.E.D.M.A.S

What I Did In This Unit

By: AS #24

2. -3 - (-7) = +4

(Do the first one you see)

Terms-Continued...

B - Brackets

E - Exponents

D/M - Division/Multiplication

A/S - Addition/Subtraction

Circumference:- The circumference of a circle is the distance around a circle.

Area:- The area of a circle is the number of square units in a circle.

3. -5 x (+3) = -15

Expanding A Bracket

4. +10/+2 = +5

Dealing with negative variables

Algebra

Algebra Equations

Terms

Algebra Responses

Diameter:- A diameter is the half of a circle. Furthermore, it's one edge to another that passes through the middle or the mid-point of a circle.

Radius:- A radius is the half of a diameter. The radius goes from the center point of a circle and to one of the edges. All distances from the edge to the middle are equal.

Multiplication and Division

However, for multiplication and division you need to do the following:

+7 x -7 = ?

First, multiply the two numbers without the sign.

7 x 7 = 49

Then, you look at the trick shared earlier. Since its a positive and a negative, it would be a negative.

+7 x -7

Last but not least, you get the answer:

+7 x -7 = -49

You do the same thing with division.

What is Order of Operation?

Tutorial

Order of Operation is the rule you need to follow to get the answer for a group of expressions.

To find the measurement of a circle, you need to look at several concepts. For example, the diameter, the radius, the circumference and the area of a circle and the Volume and Surface Area of a cylinder.

Tutorial

What is Algebra?

When solving for a variable in algebra, you do B.E.D.M.A.S backward.

Algebra is solving for an unknown variable in an equation.

Multiplying

Example:

2x - 4 = 10

First, you try to get rid of the 4, so you add 4. Since there's a negative sign in front of the 4, the 4 turns into -4. You have to add 4 on the other side to keep it balanced.

2x - 4 + 4 = 10 + 4

- 4 + 4 cancel and now you have:

2x = 14

You divide the two numbers by two because 2x is multiplying and you have to do the opposite, which is division.

2x/2 = 14/2

You get an answer of:

x = 7

Example- Order Of Operations With Integers

Addition

2³ - 4 (8 + 2 x 3 - 4)

= 2³ - 4 (8 + 6 - 4)

= 2³ - 4 (14 - 4)

= 2³ - 4 (10)

= 8 - 4 (10)

= 8 - 40

= - 32

Integers And Order of Operations

Division

What is an Integer?

An integer is a whole number that is a positive or a negative.

Subtraction

Example

You need to balance both sides with the same number.

2w + 3 = 13

2w + 3 - 3 = 13 - 3

2w/2 = 10/2

w = 5

What I Did In This Unit

Learning Goals

General Goal: To develop competency in using Order of Operations with positive and negative numbers.

Geeky Goal: To view math as a language. There are steps that need to be followed and a correct method of writing a solution.

Circumference

Circles

Diameter

Trick

After you get the answer, check:

Radius

The number you got

2(5) + 3 = 13

10 + 3 = 13

13 = 13

If the number is the same on both sides, that means you did it right.