### Days Postings

### Blog Series

### Subscribe to Blog via Email

### Copyright Notice

© Mark Biegert and Math Encounters, 2018. Publication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Mark Biegert and Math Encounters with appropriate and specific direction to the original content.

### Disclaimer

All content provided on the mathscinotes.com blog is for informational purposes only. The owner of this blog makes no representations as to the accuracy or completeness of any information on this site or found by following any link on this site. The owner of mathscinotes.com will not be liable for any errors or omissions in this information nor for the availability of this information. The owner will not be liable for any losses, injuries, or damages from the display or use of this information.

# Category Archives: General Mathematics

## Mathcad Solution To XKCD Problem

XKCD is a great comic strip by Randall Munroe that takes a quirky look at the world of science. Randall recently posted a set of questions for a substitute teacher to pose to a math class that were interesting and attracted the attention of some problem-solving enthusiasts. Continue reading

Posted in General Mathematics
2 Comments

## Propane Tank Math

I have used propane for years with my barbecue grill, but I have never used it for heating a space. While at university many decades ago, I worked in construction, and we used propane heaters to make working in partially-completed homes more comfortable in the winter. I went to Home Depot and purchased the propane heater shown in Figure 1. It is rated to put out 30K to 40K BTU/hr. This should provide enough heat to warm my garage so I can work in it comfortably. I like the fact that it is small, and I can easily store it during the summer. I have too much stuff to manage as it is, and I do not need any more big stuff. Continue reading

Posted in General Mathematics
Leave a comment

## Yet More Gift Wrapping

My sister and I talk about these practical math problems all the time. Here is another good video that covers gift wrapping with a mathematical slant. Continue reading

Posted in General Mathematics
Leave a comment

## Old Way Of Specifying Phone Wire Diameter

I still work on old copper phone networks, and today I encountered wire specified as "300 pound". I had never seen a specification like this for phone wire before. As I thought about it, this specification seemed very similar to how the diameter of thread is still specified, which is by the weight in grams of a 9000 meters of fiber – a unit of measure called the denier. Continue reading

## Letter Folding for Envelopes

I still occasionally write paper letters. In fact, I had some letters to write the other day, and I realized that was doing a bit of math when I folded the letters for placement into standard business envelopes that was worth discussing here. Figure 1 shows the business envelope that I normally use. Continue reading

Posted in General Mathematics, Origami
2 Comments

## Tree Height Measuring Example

I have been testing a number of Android applications that are intended to measure the size of objects knowing their range or vice versa. One application that I have found particularly useful is called Baumhöhenmesser – Tree Height Meter (my translation) – which is an application written by a German developer. I have found this application particularly useful, and I thought I would review its operation here. It is part of a suite of Android applications intended for forestry management. This app makes excellent use of the Android's ability to measure angles. Continue reading

Posted in General Mathematics, Geometry
3 Comments

## Stadiametric Rangefinding Approaches

Recently, I was reading about stadiametric range finding methods being used by hunters and their telescopic sights – I was surprised to find a lot of writing on the topic. As I researched the topic, I saw that there are three common approaches used in telescopic sights: milliradian (mil), Minute Of Angle (MOA), and Inch Of Angle (IOA). I will review these methods here. Continue reading

Posted in Ballistics, General Mathematics
1 Comment

## Optical SFP Power Estimation Using Curve Fitting

I was asked today how to use Excel to estimate the power usage of two optical components at case temperatures for which we had no data. I initially solved the problem in Mathcad by fitting an equation of the form $latex c_0 \cdot e^{c_1 \cdot T_{Case}}+e_2 to the data and computing the corresponding power. Continue reading

Posted in Excel, General Mathematics
Leave a comment

## Negative times a Negative is a Positive

On my team, I work hard to ensure that we have a non-threatening environment for questions – any questions. In fact, I often ask very basic questions in meetings so that I can make sure that I understand all the nuances of a situation. You would be amazed how often I learn things from asking questions so basic that you would think asking them would not be necessary. Continue reading

Posted in General Mathematics
Leave a comment

## Prime Number Magnitudes

I am responsible for some of the authentication features in our products and these features use prime numbers. People often have basic questions on prime numbers, such as:

What happens if I choose the same prime number as someone else?

Are there enough prime numbers? Continue reading

Posted in General Mathematics, software
Leave a comment