Khan Academy Lessons by Tomas Evans

Negative number rules

tevans49 — 2021-04-26 02:42:41 UTC

- x - = +
- x + = -
+ x + = +

Adding odd and even numbers

tevans49 — 2021-04-26 02:44:50 UTC

ODD + ODD = EVEN
ODD + EVEN = ODD
EVEN + EVEN = EVEN

Pythagoras Theorem

2021-04-26 02:47:14 UTC

a²+b²=c²

order to solve the brackets

2021-04-26 02:47:35 UTC

1:[->2:{->3:(
example:2[x+3{3x(32+6)}]

B O D M A S

2021-04-26 02:48:42 UTC

1. Brackets
2. Orders
3. Divisions
4. Multiplications
5. Addition
6. Subtraction

Distributive law

2021-04-26 02:48:59 UTC

x(y+z) = (x*y) + (x*z)

Stander deviation./

27ftan — 2021-04-26 02:49:03 UTC

Greater stander deviation=The wider the data spread on a line.

Exponentiation

2021-04-26 02:49:11 UTC

Exponentiation is a number that shows how many times to use that number in a multiplication. It is written as a small number to the right and above the base number.
Example, 3⁴= 3x3x3x3 = 81

BEDMAS

2021-04-26 02:50:58 UTC

Brackets
Exponents
Divisions
or
Multiplication
Addition
or
Subtractions

Variable

2021-04-26 02:52:39 UTC

Stand for an unknown number. Usually x, y, and z.

Symbols represent difference in Math

2021-04-26 02:52:54 UTC

a>b = a is more than b.
aa=b = a and be is equal.
a≥b = a is same or bigger than b.
a≤b = a is same or smaller than b.

Variables

2021-04-26 02:52:59 UTC

Area of a circle

2021-04-26 02:53:06 UTC

radius x 2 divided by 3.14

Volume of a Rectangular Prism

2021-04-26 02:53:31 UTC

To solve the volume of a rectangular prism, you have to multiply 'Length, Width, and Height' together.

V= whl

π = 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664709384460955058223172535940812848111745028410270193852110555964462294895493038196442881097566593344612847564823378678316527120190914564856692

2021-04-26 02:54:03 UTC

Volume of a cone./

27ftan — 2021-04-26 02:55:35 UTC

1/3*πr²*h

Surface area of a Sphere./

27ftan — 2021-04-26 02:56:50 UTC

4πr²=πd²

Calculating surface area example

27iwu2 — 2021-04-26 02:57:46 UTC

First you choose a side of the box 30 and 20 and multiply together, and 2x because there is two sides. You also do it for the other sides: 30x5x2, 20x5x2. At last plus them all together.
30x20x2=1200
30x5x2=300
20x5x2=200
1200+300+200=1700
The surface area is 1700.

X

2021-04-26 02:57:47 UTC

How to solve circumference.

2021-04-26 02:58:02 UTC

2 x r(radius) ÷ π = circumference

Volume of circular cone

2021-04-26 02:58:08 UTC

πr² h/3

Volume of a Cylinder

2021-04-26 02:58:42 UTC

To solve a volume of a cylinder, you have to multiply 'Radius x Radius' first and multiply π. Then multiply Height.

V= πr²h

Exponents

2021-04-26 02:59:35 UTC

a^m * aⁿ = a(m+n)

Surface area formula of cylinder

2021-04-26 02:59:43 UTC

S= 2πrh+2πr²

Circumference of a circle

2021-04-26 02:59:47 UTC

2 x pi x radius

Negative squared and cubed./

27ftan — 2021-04-26 03:00:05 UTC

-2²=4
-2³=-8
-2⁴=16
-2⁵=-32
....

How to calculate area

2021-04-26 03:00:48 UTC

Area of Rectangle: area = length x width
Area of Triangle: area = (1/2) (base) (height)
Area of Parallelogram: area = base x height
Area of Circle: π * r²

Area of circle

2021-04-26 03:01:27 UTC

πr²

The way to calculate area of a trapezoid

2021-04-26 03:01:58 UTC

(Upper base + lower base) x height ÷ 2

Volume of a sphere

2021-04-26 03:02:05 UTC

V = 4/3 πr³

Volume of cube.

2021-04-26 03:03:33 UTC

To solve volume of cube, you have to multiply the edge 3 times. (a x a x a)

V=a³

Commutative Percentages

2021-04-26 03:04:26 UTC

Because a × b = b × a it is also true that a% of b = b% of a

Example: 8% of 50 = 50% of 8, which is 4

Reflect Points

2021-04-26 03:05:37 UTC

If a point is 5cm away from the point, its reflect point is also 5cm away from the point, but going opposite side.

2021-04-26 03:05:39 UTC

To get how weight is in the water

2021-04-26 03:06:23 UTC

water's quantityX(concentration divided by 100)=amount of salt in the water

Area of triangle

2021-04-26 03:06:37 UTC

A=H*B/2

Surface area of sphere

2021-04-26 03:07:53 UTC

4πr²

The way to solve all the math problem

2021-04-26 03:08:51 UTC

Every answer can be x!!!

How to find angle in triangle

2021-04-26 03:12:28 UTC

The total has to add up to 180°

How to find the surface area of a Cone./

27ftan — 2021-04-26 03:12:39 UTC

πr²+πr√(h²+r²)

Volume of cylinder

2021-04-26 03:13:53 UTC

Volume=height times πr²

Area of trapezium

2021-04-26 03:14:17 UTC

Base a * base b divide by two and multiply by the height

Cross Multiply

2021-04-26 03:17:49 UTC

To cross multiply is to go
from this:
8/12 = 2/3
to this:
8 × 3 = 12 × 2

In Algebra:
To cross multiply is to go
from this:
a/b = c/b
To this:
ad = bc

Perimeter of trapezium

2021-04-26 03:19:35 UTC

add all the side up=P

Radius of circle

2021-04-26 03:21:02 UTC

Diameter divided by 2 = radius

Number diagonal lines

2021-04-26 03:21:32 UTC

n*(n-3)/2

Solving area of a circle

27iwu2 — 2021-04-26 03:21:34 UTC

Pie times the radius squared.
(A = π r²)

Volume of a Circular Truncated Cone./

27ftan — 2021-04-26 03:23:53 UTC

πh/3*(R²+r²+Rr)

Surface area of a Circular Truncated Cone./

27ftan — 2021-04-26 03:29:59 UTC

π[R²+r²+(R+r)l]

How to solve perimeter of all the shape.

2021-04-26 03:42:17 UTC

Add all the sides

USA coins

27iwu2 — 2021-04-26 04:19:57 UTC

A penny = 1 cent
A nickel = 5 cents
A dime = 10 cents
A quater = 25 cents
A dollar = 100 cents
half-dollar = 50 cents