29 SEP 2017 by ideonexus

Roman Arithmetic

...basic Roman arithmetic is largely rather simple, even for those of us spoiled by Arabic notation. Addition is no sweat, because complex Roman numbers already use what math pros call additive notation, with numerals set beside one another to create a larger number. VI is just V plus I, after all. To add large numbers, simply pile all the letters together, arrange them in descending order, and there’s your sum. CLXVI plus CLXVI? CCLLXXVVII, or CCCXXXII. And one of the advantages of the Rom...
Folksonomies: math mathematics education
Folksonomies: math mathematics education
02 SEP 2016 by ideonexus

Math Games

Buzz. An example of a low-stress, win-win game is Prime Number Buzz. Students stand in a circle or at their desks and go around the room in order, saying either the next sequential number if it is a composite or “buzz” if it is a prime. If they are incorrect, they sit down, but they keep listening and when they catch another student’s error, they stand up and rejoin the game. (The same game format works for Multiples Buzz, using multiples of, for example, 3, 4, and so on.) Telephone. T...
Folksonomies: education games math
Folksonomies: education games math
1  notes

02 SEP 2016 by ideonexus

Delay Method of Errorless Math Practice

Prepare a list of the calculations from the flash cards on a sheet of paper. These can be on a template, with multiplication facts at the appropriate level pulled and copied for the student. On these forms, include three columns next to each multiplication question, labeled “correct repeat,” “correct wait,” and “correct response.” Start with review and confi dence building. For example, show the question 3 × 4 = __ on the card and without any delay say the answer. Th e student re...
Folksonomies: education methodology math
Folksonomies: education methodology math

12 APR 2013 by ideonexus

The Origin of Chaos Theory

Lorenz and his team were working to develop a weather forecasting program on an early computer known as a Royal McBee LGP-30.21 They thought they were getting somewhere until the computer started spitting out erratic results. They began with what they thought was exactly the same data and ran what they thought was exactly the same code—but the program would forecast clear skies over Kansas in one run, and a thunderstorm in the next. After spending weeks double-checking their hardware and t...
Folksonomies: prediction chaos theory
Folksonomies: prediction chaos theory
1  notes

Weather modeling produced two widely different results when a few thousandths of a decimal point went missing.

12 JUN 2012 by ideonexus

Argument for Decimal Currency

[Decimal currency is desirable because] by that means all calculations of interest, exchange, insurance, and the like are rendered much more simple and accurate, and, of course, more within the power of the great mass of people. Whenever such things require much labor, time, and reflection, the greater number who do not know, are made the dupes of the lesser number who do.
Folksonomies: metric standards
Folksonomies: metric standards

Because it is simple and complex things lead to people being taken advantage of.

31 JAN 2012 by ideonexus

The Importance of Accuracy

In 1905, a physicist measuring the thermal conductivity of copper would have faced, unknowingly, a very small systematic error due to the heating of his equipment and sample by the absorption of cosmic rays, then unknown to physics. In early 1946, an opinion poller, studying Japanese opinion as to who won the war, would have faced a very small systematic error due to the neglect of the 17 Japanese holdouts, who were discovered later north of Saipan. These cases are entirely parallel. Social, ...
Folksonomies: statistics measurment
Folksonomies: statistics measurment

Comparing an error in measuring the thermal conductivity of copper to surveying Japanese after WWII.