August 12, 2019

One digit repeat, repeating number /9

Two digit repeat, repeating number/99

Three digit repeat, repeating number/999

For example:

1. 0.222222.... = 2/9

2. 0.2727272..=27/99 =3/11

3. 0.123123....=123/999 = 41/333

August 12, 2019

Sine and Cosine of complementary angles (cofunction)

sine( x ) = cos (90-x)

sine (2) = 0.034899496

this is the same answer you should get if we try to find cos (90-2) or cos (88)

lets check on the calculator

cos 88 = same . it should be 0.034899496

sin (42) = cos (...

August 12, 2019

Geometry: Pythagorean triples (memorize for success)

This is for 7th graders, 8th graders and geometry students, and SAT test takers

Pythagorean triples are integer side lengths of a right triangle. The biggest number is the hypotenuse, and the two smaller numbers ar...

August 12, 2019

Perfect Squares of two digit numbers that end with 5

Step 1 - multiply the first digit by the next consecutive integer

Step 2 - place 25 at the end of your result

Lets try an example

15 x15 = ?

Step 1 - the first digit is 1

the next consecutive integer after 1 is 2

...

August 12, 2019

11 x "a two digit number"

Step 1: let x represent the first digit and y represent the second digit. write a three digit number where the first digit "x" is the first digit , and your second digit y is your third digit. x _y

Step 2: find the sum of x and y

Step 3: pl...

April 26, 2016

Before I answer this question, let me ask you a question first. Do you know a high school graduate, or college student, who can not multiply or add without a calculator, who does not know how percentages work, or who can not spell basic words? I have been an educator f...