Notes for Homework 13, due, Mon., Dec 4

Notes on Roman numerals

Notes on repeating decimals to fractions and vice versa

Notes on decimals, fractions and percents
 

Notes for Homework 12, due Mon., Nov 27

Notes on the metric system

Changing Celsius to Fahrenheit

F = 9/5 C + 32

Changing Fahrenheit to Celsius

C = 5/9(F - 32)




 

Notes for Homework 11, due Nov. 13

Notes for CPI table, interest on savings, effective interest rate and interest on loans
 

Notes for Homework 10, due Mon. Nov. 6

Notes on mean, median and mode

Notes on the five number summary, IQR and the calculation of low and high outlier thresholds

Notes on z-scores and table lookup
 

Notes for Homework 9, due Monday, Oct. 30

Notes on simultaneous equations and Kramer's Rule

Notes for Homework 8, due Oct. 23

Notes for contingency tables

Notes for coin problems

Notes for slope, point-slope and slope-intercept 

Notes for Homework 7, due Mon., Oct 16

Notes on set theory and Venn diagrams

Notes on rates based on powers of ten, most often on the per 100,000 scale

History lesson for Wednesday quiz

Here is a link to the biographies of Von Neumann, Turing, Hopper, Dijkstra and Knuth.

Here is a link to NASA's page on Katherine Johnson.

Notes for Homework 6, due Monday Oct. 2 (not accepted late)

Notes for triangles defined by three points: area and classification

Notes for interior angle sum and regular angle formula fro a polygon with n sides

Notes for Homework 5, due Sept. 25

Classifying Triangles by the three angles -or- by the three side lengths


Finding the area of a triangle using Heron's Formula

Notes for Homework 4, due Sept. 18

Practice for bels and decibels, also the Richter scale

More on the Richter scale

Simplifying and approximating square roots

Notes for Homework 3, due MONDAY, SEPT. 11

Notes for decimal part of a day to hours, minutes and seconds.

Notes for scientific notation

Fractional part of a day

A year is defined by how long it takes a planet to make a single orbit around the sun. An Earth year is 365.2422 days. To make up for the decimal part we have a leap year every four years and skip the leap year if the number of the year is divisible by 100. This means we had leap years in 2004, 2008, 2012 and 2016, but we did not have one in 2000. What this lesson is about is to take the decimal part of this time and turn it onto hours, minutes and seconds.

Step 1. Multiply the decimal part by 24 to get the number of hours.
In this case, .2422 x 24 = 5.8128, which means 5.8128 hours.

Step 2. If there is still a decimal part, multiply it by 60 to get the number of minutes. We know know a year is 365 days, 5 hours and some number of minutes. That number is 60 x .8128 = 48.768

Step 3. If there is still a decimal part, multiply it by 60 to get the number of seconds.
We know know a year is 365 days, 5 hours, 48 minutes and some number of seconds. That number is 60 x .768 = 46.08. In these problems, it is okay to round to the nearest tenth of a second, so the final answer is 365 days, 5 hours, 48 minutes and 46.1 seconds.

Let's do another example. A year on Venus is 224.65 Earth days.

Step 1. .65 x 60 = 15.6, so the year on Venus is 224 days, 15.6 hours.

Step 2. 60 x .6 = 36, so that makes the year on Venus 224 days, 15 hours and 36 minutes. There is no more decimal part, so we don't have to add any seconds to our answer.

Here are two more practice problems. The answers are in the comments.

1. It takes Mercury 87.969 Earth days to travel around the sun. Write this number in days, hours, minutes and seconds.

2. It takes Mars 686.98 Earth days to travel around the sun. Write this number in days, hours, minutes and seconds.

Notes for Homework 2, due WEDNESDAY, SEPT. 6

Notes on hexadecimal, binary and decimal

Notes on logic with 1s and 0s

Notes on time problems

Notes for Homework 1, due August 28

Notes on rounding

Notes on significant digits

Notes on binary to decimal and vice versa

Link to the biographies of Archimedes, Newton, Euler and Gauss

Click on this link to read a post on the four great mathematicians listed above

Notes for Homework 9, due Monday, July 24

Notes on the five number summary method for determining outliers

Notes on z-scores and normal distribution
 

Notes for Homework 8, duy Wed. July 19

A quick reminder: this homework will not be accepted late because the answer sheet will be given out at the end of class to help study for Thursday's midterm.

Notes on scientific notation

Notes on Set Theory

Notes on Venn Diagrams

Notes on contingency tables and probabilities

Math history: Five Briitsh logicians

 Here is a link to stories about Boole, Babbage, Dodgson, de Morgan and Countess Lovelace

Notes for Homework 7 due Monday, July 17

Notes on simultaneous equations

Notes on using elimination in coin problems

Notes for Homework 6, due Wednesday July 12

Practice problems for distance.

Practice problems for slope, point-slope and slope intercept.

Notes for Homework 5, due Tuesday July 11

Notes for classifying triangles by angles or by side lengths

Note for finding area using Heron's formula
 
 

Link to the history of five computer scientists

A link to the biographies of Von Neumann, Turing, Hopper, Dijkstra and Knuth.

Notes for Homework 4, due Monday July 3

Notes on decibels and bels (measuring sound) and the Richter scale (measuring earthquakes)

Notes on square roots, approximate and simplified, also Pythagorean Theorem problems

Notes on rates at different scales, notably death rates per 100,000 people

 

Notes for Homework 3, due June 28

Notes on interest rates on investments, interest rates on loans and the Consumer Price Index

Notes on rounding to significant digits
 

Notes for Homework 2, due June 26

Notes for converting from binary (base 2) to decimal (base 10) and binary to hexadecimal (base 16)

Notes for the logical operators AND (^), OR (v) and NOT (~)

Converting repeating decimals to fractions in lowest terms

Time problems

Roman numerals

Notes for Homework 1, due June 21

Notes on fractions, decimals and percents, also on primes and prime factorizations.

Notes on repeating decimals and rounding decimals.

Notes on adding and subtracting time.
 

Link to the stories of four famous mathematicians

The biographical data on Archimedes, Newton, Euler and Gauss.

Notes for Homework 7, due March 27

Contingency tables and probabilities

Two points: Find slope, then the point-slope, then slope-intercept

Coin problems
 

Notes for Homework 6, due March 20

Notes on Set Theory and Venn Diagrams

Notes on interior angle sums and regular angles

Notes on tilings of the plane

Notes on the area of a triangle given three points on the plane
 

Link to the biographies of five computer scientists

Link to the biographies of John Von Neumann, Alan Turing, Grace Hopper, Edsger Dijkstra and Donald Knuth.

Notes for Homework 5, due Monday March 6

Note for classification of triangles by angle measurement and side length

Area by Heron's formula
 

Notes for Homework 4, due Wed. Feb. 22

Because of the Monday holiday, homework is due on Wednesday. There will be no quiz this week.

Notes on the Richter scale and bels and decibels, abbreviated B and dB.

Notes on square roots and the Pythagorean Theorem.

Notes for Homework 3, due Monday, Feb. 13

Practice with decimals and percents

Practice with scales of powers of ten other than percent

Practice with scientific notation
 

Notes for Homework 2, due Monday, Feb. 6

Notes on Hex to Binary and vice versa.

Notes on logical operators AND (^), OR (v) and NOT (~).

Notes on time conversion and adding and subtracting time.

Notes for Homework 1, due Monday, January 31

Links to posts on rounding.

Links to posts on significant digits.
 
Links to posts on decimal to binary and binary to decimal.
 

Link to the biographies of Archimedes, Newton, Euler and Gauss

Click on this link to a post that has the biographies of the four guys I discussed Monday night, the information that will be on the quiz on Wednesday.