PERCENTAGE BASE & RATE

MATH
YOUTUBE VIDEO

NOTE: you can say 'part' instead of 'percent'

PERCENTAGE RATE & BASE

P = R * B
R = P : B
B = P : R

20 is 50% of what number?

P*  
[is]

R:
[%]

B:
[of]

PERCENTAGE RATE & BASE works the same as DISTANCE SPEED & TIME

20 is 50% of what number?

B = P : R
B = 20 : .5 
B = 40

A train traveled 300 kilometers at 120 kph. How long did it travel?

T = D : S
T = 300 : 120
T = 2.5

20 is 50% of what number?
20:B = 50:100
20*100 = B*50
2000 = B*50
2000:50 = [40]

PERCENT OF INCREASE

Part = amount of increase
Base= original amount

The number of students learning Torah increased from 250 to 300 students. What is the percent of increase?

a:b = c:d is ad = bc

R = P : B

50:250 = c:100 
is 
50*100 = 250*c
5000:250 = c

C = 20%

PERCENT OF DECREASE
aka PERCENT OF DISCOUNT
-follows the same exact formula as PERCENT OF INCREASE

A dozen roses sale for $24. What is the price per unit?
R = P : B
R = $24 : 12

Unit price is $2

Adding a list

MATH

How to add a list of numbers

*Add as usual
*find compliments (numbers that add up to ten)

Example:
9   ١
2   ٢
3   ٢
5   ٢
1   ١
__+
20

Everyone will agree that instead of adding from top to bottom it is faster to look for numbers that add up to ten. 9 & 1 is 10 and so is 5+2 & 3

2   ٣
9   ١
4   ٢
3   ٣
6    ٢
5   ٣
1   ١
_____+
30

Checking off compliments mentally with Eastern Arabic numerals or Hebrew letters may be useful

ZIG ZAG ADDITION

MATH
YOUTUBE EXPLANATION

429
534
+____
963

*first off, mental addition always goes left to right, starting with the big number. This eliminates the need to juggle borrowing and carrying over.
*next rule is never say the word plus or minus out loud or in your head. Doing so just needlessly clutters your mind. Just repeat values
*simply add from left to right and repeat values

Example:
429
534+

Nine hundred
Nine hundred twenty
Nine hundred fifty
Nine hundred fifty nine
Nine hundred sixty three

Our answer is 963!

-It's that easy! Mental addition is just zig zagging through the problem, repeating the values in a succinct manner until you reach the end.

Let's assume you were adding money. Like 4.29 + 5.34... Simply ignore the decimal points and add normally like in the example. With money all you have to do is put in a decimal point two places from the right when finished so that you have your cents.

*IMPORTANT RULE! When adding money remove the decimal points and treat dollars as hundreds. So instead of saying 4.29 dollars say four hundred twenty nine. This allows you to perform zig zag or mental addition.

Pi

MATH

before we begin let's get in some relevant Hebrew vocabulary so that we are advancing our Hebraic education in every circumstance

circumference
HeQeF הקף

radius
RaDYuX רדיוס

diameter
Qo9eR קוטר

r: The distance from the center of a circle to any point on the circle is called the radius.

d: The distance across and through the center of a circle is called the diameter.

The diameter is always equal to twice the radius.

If the radius is 3, the diameter is 2 × 3, or 6.

The circumference of a circle is the distance all the way around the outside edge of the circle. In other words, circumference is the name for a circle's perimeter.

A long time ago an Egyptian mind took a rope and cut it equal to the distance through the trunk of a tree. He cut another rope equal to the distance around the trunk of the tree. The rope that equaled the distance around the trunk was three times as long! But wait! Not exactly! It was a little over three times. This magic number is called pi or π. It has the approximate value of 3.14.

FORMULA FOR CIRCUMFERENCE OF A CIRCLE:
πd

FORMULA FOR AREA OF A CIRCLE:
πr^2

PYTHAGOREAN THEOREM

MATH

before we begin let's get in some relevant Hebrew vocabulary so that we are advancing our Hebraic education in every circumstance

Right angle triangle
M5uLa5 Ya5aR-ZaWiT משולש ישר-זווית

Pythagorean theorem
Mi5Pa9 PiTRaGoX משפט פיתרגוס 

Hypotenuse
YeTeR יתר

The three angles inside a triangle always add up to 180°, no matter how the triangle is drawn.

PYTHAGOREAN THEOREM 

-A right angle triangle contains one angle that equals 90°.

the sides of a right triangle are always in a particular proportion which can be expressed by the formula A^2 + B^2 = C^2, in which A and B are the two shorter sides of the triangle, and C is the longer side opposite the 90-degree angle. This longer side is called the hypotenuse.

3-4-5 triangle

TESTING THE THEOREM

3^2 + 4^2 should equal 5^2. Does it? Yes! 9 + 16 does equal 25.

GEOMETRY

MATH

before we begin let's get in some relevant Hebrew vocabulary so that we are advancing our Hebraic education in every circumstance

Geometry
Ge4oMe9ReYaH גיאומטריה
perimeter
HeQeF הקף

Area of a rectangle=L × W
Volume of a rectangle=L × W × D
Area of a square=side^2
Volume of a cube=side^3
Perimeter of a rectangle=add all sides
Area of a triangle=base × height ÷ 2

A pyramid is a three-dimensional shape made of four sides that suit atop a rectangular base.

Volume of a pyramid=bh ÷ 3

Finding the volume of a pyramid is just like finding the volume of a rectangle or cube except you divide by three. Why do you divide by three? Because a pyramid is a cube with three as it's strength instead of 4.

FOIL METHOD

MATH

FOIL METHOD