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Home < Arithmetic and Number Theory Skills << 4 Remainder Arithmetic and Divisibility


4 Remainder Arithmetic and Divisibility

     1 Remainder Arithmetic Modulo 10
     2 Remainder Arithmetic Modulo 10 more
     3 Remainder Arithmetic Modulos 10 more still
     4 Remainder Arithmetic Modulo 10 in general
     5 Remainder Arithmetic Modulo 5
     6 Remainder Arithmetic Modulo 5 Properties
     7 Remainder Arithmetic Modulo 5 Examples I
     8 Remainder Arithmetic Morulo 5 Examples II
     9 Remainder Arithmetic Divisibility by 5
     10 Remainder Arithmetic Long Division by 5 Quickly
     11 Remainder Arithmetic Long Division by 5 Quickly more
     12 Remainder Arithmetic Modulo 10 Example
     13 Remainder Arithmetic Modulo 5 Example
     14 Remainder Arithmetic Modulo 9 Example
     15 Remainder Arithmetic Modulo 9 Example
     16 Remainder Arithmetic Modulo 9 Example 2
     17 Remainder Arithmetic Rule of 9 for checking sums I
     18 Remainder Arithmetic Rule of 9 for checking sums II
     19 Remainder Arithmetic Rule of 9 for checking sums III
     20 Remainder Arithmetic Rule of 9 for checking sums IV
     21 Remainder Arithmetic Modulo 3
     22 Remainder Arithmetic Modulo 3 more
     23 Remainder Arithmetic Modulo 2
     24 Divisibility Tests for 2 3 5 9 10
     25 Divisibility Tests for 2 3 5 9 10 Examples
     26 Divisibility by 2 3 5 Examples
     27 Divisibility by 2 3 6 5 9 10 Examples
     A Decimals Modular and Remainder Arithmetic

Notes

The following lessons provide a very slow, essentially prealgebraic introduction to remainder arithmetic for modulo 10, 5, 9, 3 and 2 to to explain the origin of divisibility rules for division by 2, 3, 6, 9 and 10. The lessons start with remainder arithmetic modulo 10 as decimals are based on counting in groups or powers of 10.

  1. Remainder Arithmetic Modulo 10 calculates the remainders on division by 10 for two whole numbers 5430 and 253, and then asks what the remaindeer on division by 10 will be for their sums and products.

  2. Remainder Arithmetic Modulo 10 more calculates the remainders on division by 10 for whole numbers 846134 and 25683, and then shows what the remainder on division by 10 will be for their sum.

  3. Remainder Arithmetic Modulo 10 still more calculates the remainders on division by 10 for whole numbers 846134 and 25683, and then shows what the remainder on division by 10 will be for their product

  4. Remainder Arithmetic Modulo 10 in general uses the patterns that arose in the previous lessons or examples to calculate remainders, modulo 10, for many sums and products.

  5. Remainder Arithmetic Modulo 5 calculates the remainders or values, modulo 5, of whole numbers 1 to 10. There-in lies an introduction to Remainder Arithmetic, modulo 5.

  6. Remainder Arithmetic Modulo 5, Properties describes the properties in an algebraic way, and then gives an example to illustrate the product property.

  7. Remainder Arithmetic Modulo 5 Examples I calculates the remainders, modulo 5 for 10, 230, 345, 348 and 347. The remainder for 347 is left as 7, modulo 5. The latter equals 2, modulo 5.

  8. Remainder Arithmetic Modulo 5 Examples II calculates the remainders, modulo 10 for 14583 and from the latter, the remainder modulo 5 for a 14583. The exercise is repeated for 84767 = 7 modulo 10 or 2 modulo 5. The conclusion is that each whole number its last digit modulo 5.

  9. Remainder Arithmetic - Divisibility by 5. The foregoing discussion of remainder arithmetic, modulo 5, sets the stage for recognizing divisibility by 5. There in lies a justification of the divisibility rule - a whole number is divisible by 5 when the last digit of its decimal representation is a 0 or a 5. Note the number nineteen has a decimal numeral representation 19 with a last digit 9, but the Roman numeral or reprsentation is XIX, a representation to which the divisibility rules does not apply.

  10. Remainder Arithmetic - Long Division by 5 Quickly. For each whole number, division by 5 can be done by long - or short - division methods. Here is alternative to both based on the decimal representation of the whole number.

  11. Remainder Arithmetic - Long Division by 5 Quickly more. The alternative in the previous lesson is shown again for another example.


  12. Remainder Arithmetic Modulo 10 Example gives an arithmetic expression 56 + 13×28 and calculates the remainder modulo 10 for it.

  13. Remainder Arithmetic Modulo 5 Example takes t expression 56 + 13×28 and calculates the remainder modulo 5 and modulo 9 for it. This example should be read after the next lesson on Remainder arithmetic, modulo 9.

  14. Remainder Arithmetic Modulo 9 Example . This lesson show 10, 100, 1000 and 10000 all have remainder 1, modulo 9. Then it calculates 8362 modulo 9.

  15. Remainder Arithmetic Modulo 9 Example /b>. Calculate 537, Modulo 9

  16. Remainder Arithmetic Modulo 9 Example 2. Illustration of the sum of digits rule for calculating remainders, modulo 9.

  17. Remainder Arithmetic Rule of 9 for checking sums, Example I illustrated for the sum of 537, 821 and 674.

  18. Remainder Arithmetic Rule of 9 for checking sums, Example II illustrated for the sum of 824, 560, 301 and 24.

  19. Remainder Arithmetic Rule of 9 for checking sums, Example III illustrated for the sum of 421, 321, 567 and 222.

  20. Remainder Arithmetic Rule of 9 for checking sums IV illustrate for sum of 44375 and 82621.

  21. Remainder Arithmetic Modulo 3 shows that 10, 100, 1000 and 10000 are all equal to 1, modulo 3. Then calculates 8432 modulo 3 from its decimal expansion in terms of 10, 100, and 1000 - a sum of digit rule results.

  22. Remainder Arithmetic Modulo 3 more - the question of when is a number a multiple of 3, and if not what is the remainder. Remainder arithmetic calculation, modulo 3, is applied to 4856.

  23. Remainder Arithmetic Modulo 2 calculates remainders on division by 2 for the whole numbers 1 to 10. Then calculates the remainder modulo 2, for whole numbers 3453, 5674, and 47, and arrives at a last digit rule.

  24. Divisibility Tests for 2 3 5 9 10 - Each number has a decimal form. Based on that form, we have rules for recognizing when a whole number is divisible by when of the divisors 2, 3, 5, 9 and 10.

  25. Divisibility Tests for 2 3 5 9 10 Examples - which are the numbers 45, 55, 31, 4 and 369 are multiples of 2, 3, 5, 9 10. Divisibility rules and remainder arithmetic are applied.

  26. Divisibility by 2 3 5 Examples. Test numbers 560, 382, 184, 962, 866 and 118 for divisibility by 2, 3 or 5.

  27. Divisibility by 2, 3, 6, 5, 9 , 10 and 100 Questions. Calculate the remainders of the numbers of the numbers 242, 1500, 173, 180, 37 and 600 on division by 2, 3, 6, 5, 9 , 10 and 100

Secondary Mathematics for Ages 11+, A Practical Approach for home-tutoring or -schooling, or for schools & colleges with local curriculum control. Study how to include site content - its skill development how-TOs and innovations into present or future lesson plans - some reading required.

Road Safety Messages and Questions: When and why should you face traffic when walking along a road or cycle path? Is it a good idea to hang limbs outside of cars etc? What gives more protection in a crash: a car, motorbike or bicycle? See too, the BBC-Belgium story Texting and Driving - texting & the impossible test - the article links to a gruesome utube video on the subject

The Logic of Injustice: How Texas sent an innocent man to his death - The wrong Carlos. Some judgments are irreversible. Procescution: Where and when prosectors play to win rather than for justice, guilt beyond a reasonable doubt goes unrespected due to prosecutors who putting winning first, those innocence before the law may be convicted. Some procescutors offices in continuing to accuse after a pardon due to reasonable doubt or innocent being shown, may sucessfully oppose compensaton for false convictions by asserting a pardon individual is still under suspicion. Then the pardoned individual or the latter's estate is not compensation for years or decade of improper or false imprisonment, or for execution. Site chapters on Logic
and some in Pattern Based Reason may slowly lead to greater precision in reading, applying and writing laws.

May 2012, Composition Starting: Pre-School and Primary Mathematics - Quantitative Skills, An Intellectual View, Feedback Welcome:

The 8 Most Popular Site Inlinks

20 Times Table - the most popular site page - popular pages - unexpected.
Fractions & Ratios - with lesson on raising terms to introduce & justify times, division & comparison as well addition & subtraction
Parent Center - See below
Volume 1, Elements of Reason - Intro to all site books.
What is a Variable - best for ages 13+
Written work formats for Arithmetic and Algebra - a skill method and standard!
Complex Numbers Visually - best for ages 13+
Natural Logs, Exponentials, Powers, Roots

Division of Labour: This site offers advice and directions with pointers to resources elsewhere, if known, when they help or lessen the need to write more.

Parent Center: Help your child or teen learn:

Parent-friendly Work Booklets for ages 3+ to 13 Use these or others to check or build skills. Other booklets are available but these booklets allow parents unsure of themselves in mathematics to help their children. The selection acquired in Canada is published in the USA. So it has a US orientation. In retrospect, the selection shows parents what to check with the booklets or by other ways, the choice is theirs. But in retrospect, the selection does not cover integral and fractions liquid weights and measures - ask the publishers to correct that! For ages 9 to 12 say, parents may compensate by showing boys and girls how to use weights or mass, and further measures in food preparation. Beyond that children may be shown how to measure and calculate angles, lengths and areas [proportional amounts too] directly or by using maps and plans drawns to scale. Learning how to gather and measure all the ingredients, pots and pans for a dish or a meal, along with cleaning up sets the stage for like activities or experiments in science courses, and in developing organizational skills, gives boys and girls a head start. Good luck. At the other extreme, more comprehensive than light, if your motto is McCainian: drill, drill, drill then Toronto mathematician and actor John Mighton's jump math organization has jump math workbooks for at least grades 3 to 8 for at-home and in-school use - training sessions for teachers available. Jump math has been expanding to cover older students. Jump Math Samples: plus Fractions for Grades 3-4 & Grades 5-6 [Read] Free Resources grades 1 to 8 [unread - likely to be good]. and

Mathematics Skills For Ages 3 to 14 - technical!

Skills with take home value - A few ideas

Basic skills include time-date-calendar Matters; money matters; map, plan and scale diagram matters;counting, measuring and figuring; decision making with logic and likelyhood; being careful and being aware of the domino effect of mistakes; reading and writing with precision.

Is your child able to add, subtract and multiply amounts of money, work with fractions, work with clocks and calendars, work with maps and plans, and measure length, weight-mass and volume? Schools may promote your son or daughter without providing basic skills in reading, writing and arithmetic.

Arithmetic and Number Theory Skills

Algebra Starter Lessons

1 Working With Sets
2 Formula Forward Use - Evaluation
3 Solving Linear Equations - Skip first step with students able to solve 1 eqn in 1 unknown.
4 Computation Rules and Function Notation
5 Real Numbers
6 More Less Greater Than Inequalities and Comparison
7 Axioms Logic and Equivalent Equations
8 Unifying Theme For Algebra
9 Proportionality Backwards and Forwards
10 Examples of Algebraic Reasoning
A Origins of Counting and Figuring Methods
B Real Numbers Extrinsic Development


Site coverage of formuala evaluation format, of computation rules and axioms, and of the forward and backward use of formulas and proportionality relations lessens the amount of natural talent needed to understand and explain algebra.

Geometry - maps plans trigonometry vectors

1 Maps Plans Measurement
2 Euclidean Geometry - Constructions + extras
3 Cartesian and Polar Coordinates
4 Lines and Slopes Take 1
5 What is Similarity
6 Trigonometry first steps
7 Complex Numbers
8 Unit-Circle Trigonometry
9 Lines and Slopes Take 2 with tangent function
10 Intersecting Straight Lines and Transversals
11 Parallel Straight Lines and Transversals
12 Function Translating and Rescaling
13 Vectors
14 Degrees to Radians and Radians to Degrees
15 Arc or Inverse Trigonometric Function

Pre-Teen and young teen mastery of skills and practices which should be common with map-plans-diagrams drawn to scale, contour interpretation included, has actual or potential take-home value for daily- and adult-life in solving routine problems. Elevating some practices to principles, axioms or postualates, provides a base for analytic and Euclidean geometry, an analytic view of similarity, and an efficient mastery of trigonometry and complex numbers. Right triangle trigonometry provide an analytic alternative to solving geometric problems by drawing diagrams to scale.

More Algebra

Natural-Logarithms Exponentials Powers Roots
Five Polynomial Operations
Quadratics Geometrically
Functions
5 Factored Polynomial Sign Analysis Examples
Rewriting algebraic substitution as function substitutions

The first topic leads to a full high school level theory for the forward and backward mastery of growth and decay models and for definition, range and domains of radicals, roots and powers. The next two topics make quadratics and polynomials easier to learn and teach. Site coverage of functions turns vertical and horizontal line rules into computation methods for evaluating functions.

70 Calculus Starter Lessons

Calculus Lessons Elsewhere:

  1. How to Ace Calculus: Street Wise Guide - Mostly Text.

  2. Flash Video for Calculus Phobics

They cover basic topics in ways likely to complement your notes, your textbooks and site material. When Goldilocks trespassed in the house of the three bears, she found three bowls of porridge, two not to her liking, and one just right. Different bears have different tastes. As invited guest here and elsewhere, if one or more explanations is not to liking, try another. It may be better or just right.

Unsolicited Advice

Learning to do and high marks if it comes to easy is often deceptive - light rather than deep. For that reason, students with learning difficulties determined not to let it get in their way may go deeper and farther than those with none. High marks, if the come easy, may be deceptive - provide a too light and not a deep mastery. That could have been your problem in secondary school, one that leads to comprehension shock or difficulties in calculus and more generally in the first year of college. Bon Appetite.


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Home < Arithmetic and Number Theory Skills << 4 Remainder Arithmetic and Divisibility


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