1. MEASUREMENT & DIMENSIONS
Plastic Technology

2. MEASUREMENT & DIMENSIONS
Essential Question for the Lesson
How do we use measurement?

3. READING A RULER The red lines on these rulers are marked at 1/2, and 1
The red marks on these rulers are at 1/4, 1/2, 3/4, and 1. (1/2 is the same as 2/4)
The red marks on these rulers are at 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8, and 1.
The red marks on this ruler are at 1/16, 1/8, 3/16, 1/4, 5/16, 3/8, 7/16, 1/2, 9/16, 5/8, 11/16, 3/4, 13/16, 7/8, 15/16, and 1.

4. DIVIDING FRACTIONS
In building/designing there will be several times you will need to determine half of a specific measurement. When dividing fractions by 2, we will multiply the fraction by the reciprocal of 2 which is ½.
Our numerator is multiplied by 1 and the denominator is multiplied by 2.
Ex: What is half of 5/8? *Hint: Simply double the denominator.
Answer=5/16

5. DIVIDING FRACTIONS ¾= 1/8= 5/16= 7/8= 1-11/16=
Divide the following fractions in half: ¾=
1/8=
5/16=
7/8=
1-11/16=
*Trick to divide mixed numbers:
1-11/16=? Numerator=
16x1+11=27
Denominator=
16x2=32
Answer=27/32
3/8
1/16
5/32
7/16
27/32

6. ADDING FRACTIONS
Make sure the bottom numbers (the denominators) are the same (Least common denominator)
Add the top numbers (the numerators). Put the answer over the same denominator as in step 1
Simplify the fraction
Ex: What is ¼” +5/8”?
*Hint: Find the least common denominator of each fraction.
Answer=7/8”
8 is the LCD
¼=2/8
5/8=5/8

7. ADDING FRACTIONS ½ +1/4= 1/8+3/4= 5/16+1/4= 7/8+3/16+3/4=
Add the following fractions:
½ +1/4=
1/8+3/4=
5/16+1/4=
7/8+3/16+3/4=
11/16+1/8+1/4=
3/4
7/8
9/16
29/16=1-13/16
17/16= 1-1/16

8. Converting to Feet & Inches
12”=1’
36”=1 yrd
Convert 54 ½” to feet and Inches
Record feet first!
How many times does 12 go into 54?
Then record the remaining inches.
4=48”
Answer = 4’ 6 ½”

9. Feet & Inches 20 ¼”= 26 3/8” = 34 ½” = 14 ½” + 17 ¾” = 68 ½” +25 ¼” =
Convert the following to feet and inches:
20 ¼”=
26 3/8” =
34 ½” =
14 ½” + 17 ¾” =
68 ½” +25 ¼” =
1’ 8 ¼”
2’ 2 3/8”
2’ 10 ½”
2’ 8 ¼”
7’ 9 ¾”

10. Converting Decimals ½ = .5 ¼ = .25 ¾ = .75 1/8 = .125 3/8 = .375
¼ = ¾ = .75
1/8 = .125
3/8 = .375
5/8 = .625
7/8 = .875

11. Converting Decimals 1/16 = .0625 3/16 = .1875 5/16 = .3125
7/16 = .4375
9/16 = .5625
11/16 = .6875
13/16 = .8125
15/16 = .9375

12. PRACTICE SHEET
Complete the following practice sheet individually. Be sure to make your answers are recorded in feet and inches.