USING LAYOUT TOOLS 8 th Grade Shop Skills

System of Measurement English – standard measurement in the United States, now called U.S. Customary System –Uses, inch, foot, yard, rod and mile as units –12 inches in a foot –3 feet in a yard –16 ½ feet in a rod –5,280 foot in a mile

System of Measurement Metric System – used for scientific work in the United States –Measurements are based on the meter –1 Meter = 100 centimeters (cm) –1 Meter = 1,000 millimeters (mm) –1000 Meters = a Kilometer (km) Units are in multiples of 10

Inch as a Unit of Measurement Traditional unit for woodworking and metalworking Some fine rules or scales have 32 marks per inch. Most rules have 16 marks per inch with each mark equaling 1/16 of an inch.

How To Read a Ruler Identify how many marks there are to an inch. Measure item and count how many marks past a whole number. Reduce to least common denominator

Reading a Ruler How many marks are there to an inch on this ruler? –16

Reading a Ruler Locate the marks for 1”, 2”, 3” and 4” Inch marks are the longest, usually the number is located under or to one side of the line.

Reading a Ruler Look at the lengths of the lines to determine measurement. –The longest line is for a whole number 1 –Next longest line is for 1 /2 –Next longest line is for 1 / 4 and 3 / 4 –Next longest line is for 1 / 8, 3 / 8, 5 / 8 and 7 / 8 –Remaining lines are 1/16, 3/16, 5/16, 7/16, 9/19, 11/16, 13/16, 15/16

Make Your Own Ruler On the strip of paper given to you, write 0 on one end and 1 on the other. Fold in half and draw line on the crease, write 1 / 2 at the crease. Fold in half again. The creases created are 1 / 4 and 3 /4 Fold in half again to get 1, 3, 5, 7 /8 th Fold in half again to get 1,3,5,7,9,11,13,15, 16ths

Reading A Ruler The Letter A represents what measurement? –1”

Reading A Ruler The Letter B represents what measurement? –1 7/16”

Reading A Ruler The Letter C represents what measurement? 1 14/16” or 1 7/8”

Reading A Ruler The Letter D represents what measurement? 2 11/16”

Reading A Ruler The Letter E represents what measurement? 3 1/16”

Reading A Ruler The Letter F represents what measurement? 3 5/16”

ONLINE PRACTICE mlhttp:// ml

Working With Fractions What is a fraction? –It is a portion of a whole –They have a numerator (Top Number) –And a denominator (Bottom Number) –1 / 2 would mean 1 part of 2

Working With Fractions Online on.htmlhttp:// on.html

Adding Fractions With common (same) denominators –Add nominator –Denominators stay the same ¼ + ¾ = 4/4 3/8 + 5/8 = 8/8 3/16 + 7/16 = 10/16

Adding Common Denominators 1 / / 4 = 2 / 4 3 / / 4 = 6 / 4 1 / / 8 = 4 / 8 5 / / 8 = 12 / 8 1 / / 8 = 6 / 8 3 / / 16 = 6 / 16 1 / / 16 = 6 / 16 7 / / 16 = 12 / 16

Adding Fractions Online Add Fractions With Like Denominators using CirclesAdd Fractions With Like Denominators using Circles

Adding Fractions With uncommon (different) denominators –One or both fractions will need to changed so both will have a common denominator 3/8 + 3/16 –First change 3/8 to 6/16 by multiplying both the numerator and denominator by 2 6/16 + 3/16 = 9/16

Adding Uncommon Denominators 1 / / 4 = 3 / 4 1 / / 8 = 5 / 8 1 / / 16 = 9 / 16 1 / / 8 = 3 / 8 1 / / 16 = 5 / 16 1 / / 16 = 3 / 16 3 / / 2 = 11 / 16 5 / / 8 = 11 / 16

Adding Uncommon Denominators Circle.htmlhttp:// Circle.html

Reducing Fractions Reduce fractions to their least common denominator. Divide the numerator and denominator by the same number so both are whole numbers. 4 / 8 = 1 / 2 (both 4 & 8 can be divide by 2) 5 / 8 = 5 / 8 (cannot be divide and remain a whole number)

Reducing Fractions 2 / 16 = 1 / 8 4 / 16 = 2 / 8 = 1 / 4 6 / 16 = 3 / 8 8 / 16 = 4 / 8 = 1 / 2 10 / 16 = 5 / 8 12 / 16 = 6 / 8 = 3 / 4 14 / 16 = 7 / 8 16 / 16 = 1

Reducing Fractions le.htmlhttp:// le.html x.asphttp:// x.asp

Adding Compound 1 st Method –Convert the whole numbers to fractions and add like or common denominators 1 3 / / 8 = 11 / / 8 = 32 / 8 = 4

Adding Compound Fractions 2 st Method –Add the fractions together then add the whole numbers to the fraction 1 3 / / 8 = 3 / / 8 = 8 / 8 = = 4

Adding Compound Fractions rcle.htmlhttp:// rcle.html

Subtracting Fractions With common (same) denominators –Subtract nominator –Denominators stay the same 3/4 - 1/4 = 2/4 5/8 - 3/8 = 2/8 7/16 - 3/16 = 4/16

Subtracting Common Denominators 1 / / 4 = 0 / 4 3 / / 4 = 0 / 4 3 / / 8 = 2 / 8 7 / / 8 = 2 / 8 5 / / 8 = 4 / 8 3 / / 16 = 0/ 16 5 / / 16 = 4/ 16 7 / / 16 = 2 / 16

Subtracting Fractions Online

Subtracting Fractions With uncommon (different) denominators –One or both fractions will need to changed so both will have a common denominator 3/8 - 3/16 –First change 3/8 to 6/16 by multiplying both the numerator and denominator by 2 6/16 - 3/16 = 3/16

Subtracting Uncommon Denominators 1 / / 4 = 1 / 4 1 / / 8 = 3 / 8 1 / / 16 = 7 / 16 1 / / 8 = 1 / 8 1 / / 16 = 3 / 16 1 / / 16 = 1 / 16 1 / / 16 = 5 / 16 3 / / 16 = 1/ 16

Subtracting Uncommon Denominators

Subtracting Compound Fractions 1 st Method –Convert the whole numbers to fractions and subtract like or common denominators 2 5 / / 8 = 21 / / 8 = 10 / 8 = 1 2/8 1 1/4

Subtracting Compound Fractions 2 st Method –Subtract the fractions then subtract the whole numbers then add results together –2 5 / / 8 = 5 / / 8 = 2 / 8 2 – 1 = / 8 = 1 2 / 8 or 1 1/4