Introduction to Engineering and Technology Concepts Unit Eight Chapter Three – Standard Measurement

Instructions for Success: Each chapter of every unit will begin with a “Mindjog.” This is a warm up question that you should answer in your workbook in the proper chapter. Please take notes as you move through the presentations in the notebook that has been provided. Sections will come up in each presentation with an assignment notice. Turn to the section detailed on the slide in your workbook and complete the assignment before proceeding. Good luck!

Objective Students will utilize standard measurement by applying it to a rule.

Mindjog! On your worksheet, please respond to the following question: “When laying down beams and joints in West Point Bridge Designer, you and your team mate probably did not take into account measurement, only cost, correct? How important is getting these beams the correct size?”

Measurement We discussed measurement in Chapter Two and stated that there are two types of accuracy: standard and precision. Many production settings do not require precise measurement. Standard measurement is often given to the foot, inch, or fraction of an inch. However production applications need a more precise size. Think about laboratory testing, metals, and specific parts. Using standard accuracy and the US Customary System, we are going to do some basic ruler measurements (Wright, 2004).

Why? Learning how to properly measure with the ruler is a common tool that you will use in everyday life, and you and your partner may want to request a ruler when building your bridge. It will help to make sure all of your angles are the same size, decreasing possible issues that might arise in the bridge otherwise (Wright, 2004).

The Ruler Below is a the edge of a ruler that is shown going up to 3 and ½ inches (or 3” 1/2, 3.5”). These next few slides will define what each of the marks on the ruler means. 123

Sixteenths Each mark on the ruler, or “rule,” is called a sixteenth. In one inch, there are 16 sixteenths. As a fraction, that is 16/16. 16/16, as with any number over itself, is one whole. Therefore, 16/16 equals one whole, or one inch. You will see an arrow highlighting all the sixteenths and then you will see the marks in the ruler change color, showing you the sixteenths. 123

Eighths Every other sixteenth is called an eighth. There are 8 eighths in an inch (8/8 = 1”). The arrow will now appear, showing you the eights. 123

Eighths (continued) Remember that some eights can be reduced, unlike sixteenths, the lowest numbers on the rule. For instance, if you were measuring something that was 4 eighths of an inch, you’d have ½. How? Essentially, you see how many times the numerator (top number) goes into the denominator (bottom number) Because: Four divides into four one time, and it divides into eight twice, or one half.

Quarters Every fourth mark on the ruler is called a quarter. There are 4 quarters in 1”. Like eighths, some quarters can be reduced. Let’s see which marks are quarter marks. 123

Halves Every eighth mark on the ruler is called a half. There are 2 halves in 1”. Let’s see where the halves are on the rule. 123

Whole Numbers Every sixteenth mark on a rule is a whole number. Let’s see the whole numbers. 123

Actual Measurement One perfectly fine method of measuring is to lay an object beside a ruler and count every mark. 123 Consider that the pen already reaches past the 1” mark, but not beyond the 2” mark. Therefore, we know that it is 1” and something…now let’s count. It looks to be around 1 and 10/16 of an inch. While this is correct, notice that you have an even number over another even number in the fraction. It can be reduced.

Reducing Fractions With the pen example, we have a measurement of 1 and 10/16 of an inch. Normally, when you have an even number over another even number, it can be reduced into a smaller form. What number goes into both ten and sixteen? Two. Two divides into 10 five times where it divides into 16 eight times. The number five cannot be divided by any other number, therefore our faction is in its smallest form. The measurement should now read: 1 and 5/8 inch. Let’s look at another way to measure this pen.

Actual Measurement Instead of counting every sixteenth of an inch, we could note that the mark the pen ends on looks like an eighth. We could simply count the eighths (or every other mark) until we reached five eights. 123

Final Example Let’s measure a sunflower. 123 It looks just under one inch. We know that there are 16 sixteenths in 1”, therefore this sunflower appears to be around 15/16 th of an inch. 15/16 th do not share any common numbers that they can be reduced by, therefore the answer is 15/16.

Assignment #1 Please turn to the section in your workbook entitled, “Unit Eight, Chapter 3 – Standard Measurement.” Complete the extension questions under the “Assignment #1” header before moving onto the next section of slides.

BEFORE MOVING ON: Did you complete the “Assignment #1” Section under the “Unit Eight, Chapter Three – Standard Measurement” section of your workbook? If you have, please proceed to the next slide.

Unit Eight Completed! Please close this presentation and let your instructor know that next class you and your partner are ready to enter the Technology Education Laboratory. After you complete the bridge building exercise, you launch “Unit Nine, Chapter One.”

References Wright, R. (2004) “Technology” The Goodheart-Willcox Company, Inc.