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YOU are better than YOU think. Show
yourself how:
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Read logic
chapters 1 to 5 in online volume Three
Skills for Algebra for greater skills & confidence
in work
and study.
Read notes and textbooks like a lawyer, so that no nuance, no subtlety and no clause escapes your attention. |
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Logic
chapters 1 to 5 re- appear not in sequence, as is or longer,
in Volume 1A, Pattern Based
Reason, Bon Appetite.
Logic
Mastery
Amazing, Amusing, Amorous, Delicious, Delightful, Edifying,
Strengthening Elixir.
It eases work & learning difficulties Makes the hard easier. Opens eyes.
Leads to greater precision.
in reading and
writing
Logic
mastery makes the hard, easier. Logic
mastery leads to better, stronger and richer comprehension. Logic
mastery improves reading and writing. Logic
mastery ease learning difficulties. Logic
mastery gives a headstart. In sum, logic
mastery will develops critical thinking, improve reading and writing,
and give a firmer base for work and studies at many levels. Good luck.
After logic,
(a) continue reading Three
Skills for Algebra, chapters 8 to 14 and do so alongside site area on solving
liinear Equations ; or (b) see this calculus
starter lesson and Volume 3, Why
Slopes & More Math, chapters 2 to 6;
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Caution: Site advice is approximately
correct, for some circumstances, not all. That leaves room for thought |
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What may be learnt and when depends on how skills
and concepts are developed. Making the hard easier and clearer will allow
earlier & richer development of skills and concepts.
Try the Twiddla
Whiteboard. In principle, it allows
to people to draw and chat together online on a copy of this webpage or a clean
sheet. The chat may be via text or audio. Visit www.twiddla.com
to set up whiteboards to work with the webpage of your choice.
For online automated help in senior high school maths & calculus,
visit quickmath.com For Automatic
Calculus and Algebra Help with derivatives, integrals, graphs, linear equations,
matrix algebra, visit calc101.com
With overlap, each site quickmath
& calc101offers a different range of
services, some free, some not, all based on webmathematica. Good luck.
| |
Column Multiplication Method
The association of products of whole numbers with counting
sub-rectangular divisions of a larger rectangle leads to visual aids for
developing and applying the generalized distributive law for whole numbers,
fractions, proper or not, and nonnegative real numbers in general.
The following animated example gives another area based example of how to
example a product of two factors, when each factor is a sum of positive terms or
lengths.

Problem: How do we express a product
NM = (a+b+c)(e+f+g)
as a expression of the terms a to g?
Solution: The number NM gives the area A of the blue rectangle -
first calculation thereof.
The BLUE rectangle can be divided into subrectangles
|
a |
b |
c |
|
e
|
ea |
eb |
ec |
| f |
fa |
fb |
fc |
| g |
ga |
gb |
gc |
Next sum all sub rectangle areas, row by row.
|
a |
b |
c |
Row Sums |
|
e
|
ea |
eb |
ec |
ea + eb + ec |
| f |
fa |
fb |
fc |
fa + fb + fc |
| g |
ga |
gb |
gc |
ga + gb + gc |
So then the area A = ea + eb + ec+ fa+ fb +fc +ga + gb + gc as well.
That gives the second calculation of area. Therefore
(a+b+c)(e+f) = ea + eb + ec+ fa+ fb +fc +ga + gb + gc
as we assume different way of a calculating an area give the same value.
Remark 1: The foregoing visual or geometric
derivation the generalized distributive law holds for non-negative
rational and irrational numbers a to f with unit length in place of the word
rows and columns if we derive and then use the additive properties of area -
the area of a rectangle equals the sum of areas of a set of subrectangles
covering it - subrectangles which intersect only at their edges. Details
will be given later.
Column Methods for Multiplication
We may replace the rectangles above by multiplication tables in which
the terms in the factors provide the initial entries in rows and columns.
|
a |
b |
c |
Row Sums |
|
e
|
ea |
eb |
ec |
ea + eb + ec |
| f |
fa |
fb |
fc |
fa + fb + fc |
| g |
ga |
gb |
gc |
ga + gb + gc |
Further table entries are obtained via products. The foregoing can be
tabulated as a column method for multiplication:
a + b + c
e +
f
x
ea + eb + ec
= product of first row with e
fa + fb + fc
= product of first row with e
fa + fb + fc
+ = product of first row with f
ea + eb + ec+ fa+ fb +fc = (e+f)(a+b+c) or (a+b+c)(e+f)
as multiplication is commutative
Remark: Even though the justifications above are only for positive
real numbers, the calculations holds for real numbers.
While the principle of permanence of algebraic form
or patterns was not a valid logical principle in the development or proof
of properties of growing sets of numbers from natural numbers to real
and complex numbers, in education the accidentally permanence of
algebraic form can be a pedagogical tool in the development of algebraic
skills and concepts. Assuming that counting by grouping and the measure
of perimeters, areas and volumes is independent of how counted or calculated.
That provides a quick logical base for algebraic reasoning in the case of
positive quantities, those identifiable with counts or measures. All the
foregoing may lead to a logical development of algebra in which justifications
are given for calculations involving positive quantities while students are
informed that justification for general case involving positive, zero and
negative quantities is a subject for further advanced study.
Students or teachers insist on the justification for general case, that is
real numbers instead of only positive numbers, can develop proofs that apply
mathematical induction and the distributive law, pattern or axiom for real
numbers. Go to the site Number
theory areas to learn
more when you have time to spare
| |
www.whyslopes.com
Analytic Geometry
& Functions, etc
Area Entrance
Entrance + Pages Below this page
Pages at Current Level (P) Area View of Products (P) Multiply, Add, Subtract (P) Long Division I (P) Long Division II (P) More Column Methods
Area Entrance (C) Complex Numbers (FN) What are Functions? (FN) Functions - More SZM: Sign Analysis (L) Lines Summary (P) Polynomials (*,+,-) (Q) Quadratics (D) Simplify Square Roots (T) Unit Circle Trig Conic Sections Links More Links
Pages at Above this Page
Extras: Not all perfect.
Equal Sign Use/Abuse Real Numbers Say More Positive Linear Inequalities Triangle Inequality Absolute Value |x| |x| Eq'ns & Inequalities Rectangular Coords Shortest Path Distance Formulas Add & Multiply Points Polar Coordinates Radians (A) Vectors (A) Coordinate Arithmetic (A) Navigation on Maps (A) Addition Geometrically (A) Rotation (PT) Translations (PT) Dilatations PT: Rotations
Links to Site Pages outside this site area follow - co- and pre-
requisites.
Road
Safety Message
Easy Consequences of this (newest) Complex
Number. Starter Lesson follow below to provide an alternate
development of HS or college maths.
Vec & Cmplx No Applet
B2 C. Conjugates
B3 Pythagoras
B4 Distance
B5 Rt Triangle Similarity
B6 Trig., Functions
B7 Dot & Cross Products
B8 Cosine Law
B9 Exponential & cis fns
B10 Easy Trig Identities
B11 Set Viewpoint
Arithmetic Videos - Real Player Format
Decimal Addition Methods
Decimal
Subtraction Methods
Decimal
Multiplication Methods
Decimal Division Methods
Fractions
Primes
Greatest Common Divisor
Divisors
Least Common Multiples
Square Root
Simplification
Using formulas forwards
& Backwards - A unifying theme for algebra skill development - the 4th
skill in Volume 2, Three
Skills for Algebra!
What
is a Variable?
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