Common mistakes in math

Use a calculator to evaluate:

image002

INCORRECT:    Enter:          18 : 3 x 2

CORRECT:   Enter:           18 : 3 : 2 = 3

CORRECT:    or Enter:      18 : (3 x 2) = 12

///////////////////////////////////////////////

Calculate:

image004

INCORRECT:       Cancel out the 3’s from the numerator and the denominator.  5 / 1 = 5

CORRECT:  (3 + 5) : (3 + 1) = 8 / 4 = 2

You cannot cancel out the 3’s in the above example.  You can cancel the 3’s only if it is multiplication:

image006

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

expo

You cannot add the exponents in the above example. You can add the exponents only if it is a multiplication:

expo2

<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

exp

 

(((((((((((((((((((((((((((((((((((((((((((((((((((((

fac

 

(((((((((((((((((((((((((((((((((((((((((((((((((((

INCORRECT CALCULATION:

image008

CORRECT CALCULATION:

image010

 

*******************************************

Subtract (-2) from (7)

INCORRECT:  7 – 2 = 5

CORRECT:  7 – (-2) = 7 + 2 = 9

 

 

[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[

INCORRECT CALCULATION:

image012

CORRECT CALCULATION:

image014

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Evaluate:  6 x 3 + 2

INCORRECT CALCULATION:   6 x 3 + 2 = 6 x 5 = 30

CORRECT CALCULATION:   6 x 3 + 2 = 18 + 2 = 20

+++++++++++++++++++++++++++++++++++++

sq

 

===================================

sin

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

squ

 

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

trig

 

%%%%%%%%%%%%%%%%%%%%%%%%%%%

ro

Comments are closed