Appetizers and Lessons for Mathematics and Reason (www.whyslopes.com)
||Définition d'une variable || Algèbre || Arithmetique || Logique ||La raison basée sur les règles et modelés||

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1,  Elements of Reason.
1A. Pattern Based Reason 
1B. Math Curriculum Notes
2. Three Skills for Algebra
3. Why Slopes & More Math

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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

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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.

Implication Rules
Chapter 4

Previous: Chapter 3, Elements of Reason

In this chapter, you will meet two puzzles. They show the difference between one- and two-way implication rules. Mastering the difference is a simple, first step, in rule and pattern-based thought. This first step is needed to precisely read rules, definitions and statements in all disciplines, including mathematics.

Are you a careful thinker? Can you understand exactly the meaning of a rule or pattern? Instructions for building or creating provide rules and patterns which say and suggest that when this is done, that should happen. Every cook and dressmaker knows the importance of following instructions carefully. Instructions and suggestions which are not repeatable and results which are not reproducible are not of interest to a cook or dressmaker.

To read rules carefully, do not imagine too much. To decide or choose among opinions and actions, you must understand the exact meaning of written and spoken words. You need this skill to understand, to follow, to write and to change rules, guidelines, instructions and laws, etc.

Use your imagination in language courses. Use your imagination when you are reading novels (and newspaper opinion columns). When reading newspapers or listening to radio and television ask: Is the story presented in a one-sided way? Headlines may suggest conclusions which are not in the stories or the text. Look at the details. Here imagination allows you to guess what the full story might be. But imagination provides only suggestion, not proof. Confidence in suggestions must come after proof is given, not before.

Also use your imagination for poorly written rules to guess their meanings. Guesses and speculations give possible meanings. These may or may not be correct. Proof and evidence, or tests, may decide which among various possibilities, if any, are correct.

Each of us needs to understand fully or as much as is possible, whatever we might be doing or learning. In reasoning, some rules and patterns are reliable. Others are guidelines. Each of us needs to know which is which.


Next Subsection: First Puzzle

Chapter Subsections: First Puzzle ] Second Puzzle ] One- Versus Two-Way ] Talking About Logic ] Implications vs Suggestions ] One Versus Two Way Committments ] Repeatable & Reproducible ] Limits and Benefits ] Accidental Rules ] Steps for Better Reason ]


Teachers: Read the following before, besides or after the two logic puzzles in this chapter, as you like. (Material not in printed version follows)

Explaining the difference between the meaning of If A then B and   B if and only A is the purpose of the following two logic puzzles.  The questions in the puzzle below are intended to introduce and emphasize the difference.

Suppose the following:

  1. the local store sells a newspaper if John enters.
  2. the same store sells a newspaper if Jeremy enters.

Then we cannot state

the local store sells a newspaper if and only if John enters it (the local store). .

since the local store also sells a newspaper if Jeremy enters.

So there is a difference in meaning between the two suggestions or statements

  1. the local store sells a newspaper if John enters.
  2. the local store sells a newspaper if and only if John enters it (the local store). .

Seeing the difference in meaning in this simple example  is the key to precision reading and writing.

More generally,  there is a difference in meaning between the two suggestions or statements

  • situation B  arises if and only if situation A arises
  • situation B  arises if situation A arises.

Here we may say occurs or happens instead of arise, or omit the word arise altogether. That be said and done, we make the convention that the two statements

  • Situation B  if situation A  (B if A form)
  • If situation A then situation B (if A then B)

have the same meaning.

 Here we assume that the two following two statements have the same meaning:

  • B if and only if A,
  •  A if and only B

 mean the same. 

 Understanding there is a  difference in meanings is the key to greater precision and exactness in work and study.  If you see the difference, you will we hope make an effort to respect the difference and use the difference in following and writing rules or instruction. 

Postscript: October 2006. We may know the following:

Situation A occurs if situation B occurs

We may not know if there are furthers situations C such that

Situation A occurs if situation C occurs.

When further such situations C are possible. we cannot use the two-way implication rule

Situation A occurs if and only if situation B occurs.

The foregoing observation provides an alternative starting point

 


Next Subsection: First Puzzle

Chapter Subsections: First Puzzle ] Second Puzzle ] One- Versus Two-Way ] Talking About Logic ] Implications vs Suggestions ] One Versus Two Way Committments ] Repeatable & Reproducible ] Limits and Benefits ] Accidental Rules ] Steps for Better Reason ]


www.whyslopes.com
Volume 1A, Pattern Based Reason

 Chapters 1 to 24

FOREWORD
Three Remarks

1 Introduction
2 Communication
3. Elements of Reason
4 Implication Rules
5. Deception
6 Chains of Reason
7 Longer Chains
For & From Consistency
8. Language Change
9 Next Chapters
10 Responsibility
11 Accidental Patterns
12 Knowledge Islands
13 Euclidean Logic
14 Deductive & Empirical Views of Mathematics
15 Objectivity
16 Origin of Rules
and Patterns
17 Objective Ways

18. Waking up
19. Symbols  & Logic
20. Pronouns or Symbols
21. Truth Tables I.
22. Truth Tables II
22. Biconditional
22. Contrapositive
23. IF-THEN table
24. Indirect Reason Again

To reason often means to persuade someone of the need for an idea or action. That someone could be yourself. So be careful.

Vol 1A Postscripts
- online only

+Proof by Absurdity alias proof by contradiction
+How the demand for consistency supports the law of the excluded middle

There is a difference between
knowing how to spend money,
and having money to spend.

There is likewise a difference
between mastering a skill
and having meeting a situation in which it applies.

 



 


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