October 2019 M T W T F S S « Sep 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Subscribe to Blog via Email
© Mark Biegert and Math Encounters, 2019. 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.
DisclaimerAll 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.
Author Archives: mathscinotes
I spend quite a bit of time at a cabin I have built in northern Minnesota. Technically, I spend most of my time in the garage on the site and I have decided that I need to be able to watch the local television stations in Duluth. These stations are ~75 miles away and I need to determine the bearing along which to point my antenna. This seemed like a good Excel exercise that I can also use as an example for those I tutor at the Hennepin County Library. There are web calculators available that perform this calculation (example), but it is more fun doing it myself. Continue reading
In this post, I will use Power Query )PQ) to gather (aka web scrape) the US Medal of Honor (MOH) recipient names, rank, service, and conflict from a website called the Congressional Medal of Honor Society (CMOHS), which states that there have been 3505 MOH recipients. They have a beautiful website with the records stored on 140 ages with 25 names per page and one page with 5 names. Normally, I would use Python to scrape a large number of web pages but I am trying to use PQ more because my customers all have Excel. My approach as a contractor is always to work within the existing infrastructure of my customers. A copy of my workbook is available here. Continue reading
I have been tutoring math at the local library and using Excel as a vehicle for encouraging people to explore everyday math. While at the library, I heard a young man ask "How many Friday the 13ths are in a year?" Since I am always looking for computational examples, I showed him how to use Excel to find the answer for himself. This post shows how I taught him to solve the problem. The solution turned out to be a good example of using Excel's date and array capabilities. Continue reading
I recently finished a job where the customer wanted an Excel dashboard that displayed metrics for test case completion and various success metrics. This dashboard contained many control shapes that I wanted to be centered in cells. I do not like to manually adjust objects so I googled for a VBA routine that would center a shape. I soon found a nice piece of code by HipGecko on the Mr. Excel forum that centered pictures in the active cell. A simple modification of this code allows it to center shapes, an object type that includes pictures and controls. Continue reading
I have been tutoring math and physics at the local library for the last few months. As part of this tutoring, I have been looking for good graphics that illustrate basic science concepts. One common high-school physics problem involves computing the tension in ropes tied to an anchor by a pulley. Figure 1 is a graphic that nicely illustrates the tension relationship between two ropes connected to an anchor point by a carabiner. Continue reading
This post will cover how to measure a countersink angle using gage balls. Figure 1 shows how a countersink is normally specified on an engineering drawing. I frequently use countersinks in my wood and metal working hobbies. In addition, using gage balls to measure the countersink angle provides a good example of how to apply basic geometry concepts to a practical problem. I use this example in my role as a volunteer adult math tutor at our local library. Continue reading
While looking for some good summer history reading, I found the book America's Hundred Thousand: U.S. Production Fighters of World War II. This book covers the production miracle associated with scaling up up the US aircraft industry to supply planes for every front during WW2. Its title refers to the fact that the US produced ~100K fighter aircraft during WW2, which lasted for 44 months for the US (Figure 2). I decided that I would look at the numbers for all forms of aircraft produced by the US during WW2. Fortunately, the Hyperwar website has put the Army Air Forces Statistical Digest online, which gives me easy access to the data. The Digest contains aircraft production data for both the US and Canada. Figure 1 shows the production numbers for the 11 categories of aircraft production listed in the Statistical Digest. In addition to 100K fighter aircraft, there were nearly 200K of other aircraft manufactured as well. Continue reading
I have been working as a contractor for the last few months and it is now time for me to make a quarterly tax payment to the folks at the Internal Revenue Service (IRS). This involves using some tables listed on Form 1040ES (see Appendix A). The US tax code uses has a graduated tax rate; the tax rates on higher amounts of income are higher than on lower amounts. As I calculated my tax payment, I became curious as to my effective tax rate. I am going to use Excel to duplicate a graph that I saw on the Wikipedia. My version of the graph is shown in Figure 1. Continue reading
I currently am doing some contract work as a system engineer. In this role, I am working on generating and managing lists of requirements to drive the engineering design work. The requirements are stored in a database that I query to generate requirements lists for specific subsystems, like a receiver or transmitter assembly. These requirements are disseminated to the engineers in various subsystem documents (Figure 1). Continue reading
I have been working on improving my web scraping abilities by analyzing WW2 data. I have focused on topics related to how the US took the 14th largest military in the world and in roughly 18 months turned it into a military that could fight anywhere in the world. In this post, I want to look in detail at how war materials were delivered to beaches around the world using a vessel called a Landing Ship Tank (LST). I have wanted to write about the LST for a while, but the web data was distributed on about 1200 separate pages – one for each ship. While a Python script would have worked nicely, I wanted to try gathering the data without doing any programming. I found some software that did a good job automating this task, which I will discuss later in this post. Continue reading