Name: ______________________ Date: __________ Station: ______
Lesson 5.13, one day. Every dollar figure on this sheet is written for class and marked [update].
The formula: cost per wear = price divided by the number of times worn. The answer is in dollars per wear.
Word bank: price, wear, divide, seam, thread, button, strong
Turkish: fiyat, giyme, bölmek, dikiş yeri, iplik, düğme, sağlam
Portuguese: preço, uso, dividir, costura, linha, botão, forte
Spanish: precio, uso, dividir, costura, hilo, botón, fuerte
Part 1. The three worked problems
Show the division. Write the unit on every answer.
(a) The jeans. A pair of jeans costs $60 [update]. You wear them 200 times before they wear out.
$60 ÷ 200 wears = $__________ per wear
(b) The shirt. A shirt costs $15 [update]. You wore it 5 times and then stopped wearing it.
$15 ÷ 5 wears = $__________ per wear
(c) The coat. A winter coat costs $90 [update]. You wear it for 3 winters.
First you have to estimate. How many times do you wear a winter coat in one winter? ________ times
So 3 winters is 3 × ________ = ________ wears
$90 ÷ ________ wears = $__________ per wear
Which of the three cost the most per wear? ______________________
Which one had the lowest price? ______________________
Write one sentence about what those two answers together tell you: ________________________________________________
Part 2. What makes a garment last
Fill in what a good one looks like and what a fail looks like.
| Factor | What to look for | A good one | A fail |
|---|---|---|---|
| 1. Fiber | Read the label. What is it made of, and in what percentages? | ||
| 2. Seam type | Look inside. One row of stitching, two rows, or a raw edge wrapped inside? | ||
| 3. Stitches per inch | Put the ruler on a seam and count one inch. | ______ per inch is good | ______ per inch is low |
| 4. Reinforcement at stress points | Look where the body pulls: pocket corners, belt loops, underarms, knees, where a strap joins. | ||
| 5. Buttons and closures | Pull the button gently. Run the zipper. |
Seam words to know
- Single-needle seam: one row of stitching. It is the first seam to open.
- Double-needle seam: two parallel rows. It holds much better.
- Flat felled seam: the raw edges are folded and wrapped inside, then stitched through. The strongest of the three. Look at the outside side seam of a pair of jeans.
- Serged edge: thread looped over the raw edge to stop it fraying. That is a finish, not a seam. A serged edge alone does not hold two pieces together.
- Bar tack: a short, dense line of stitches at a stress point, like the corner of a pocket.
- Stress point: anywhere the body pulls on the garment.
Part 3. Quality inspection, four garments
Run all five checks on each garment your station gets. Check the box if the answer is good. Write the number where a number is asked for.
Garment 1: ______________________
| Check | Finding | Good? |
|---|---|---|
| Fiber (from the label) | [ ] | |
| Seam type (single, double, flat felled, or serged only) | [ ] | |
| Stitches per inch | ______ per inch | [ ] |
| Reinforcement at a stress point (name the point) | [ ] | |
| Buttons and closures | [ ] |
One sentence: this garment will or will not last, because ________________________________
Garment 2: ______________________
| Check | Finding | Good? |
|---|---|---|
| Fiber (from the label) | [ ] | |
| Seam type | [ ] | |
| Stitches per inch | ______ per inch | [ ] |
| Reinforcement at a stress point (name the point) | [ ] | |
| Buttons and closures | [ ] |
One sentence: this garment will or will not last, because ________________________________
Garment 3: ______________________
| Check | Finding | Good? |
|---|---|---|
| Fiber (from the label) | [ ] | |
| Seam type | [ ] | |
| Stitches per inch | ______ per inch | [ ] |
| Reinforcement at a stress point (name the point) | [ ] | |
| Buttons and closures | [ ] |
One sentence: this garment will or will not last, because ________________________________
Garment 4: ______________________
| Check | Finding | Good? |
|---|---|---|
| Fiber (from the label) | [ ] | |
| Seam type | [ ] | |
| Stitches per inch | ______ per inch | [ ] |
| Reinforcement at a stress point (name the point) | [ ] | |
| Buttons and closures | [ ] |
One sentence: this garment will or will not last, because ________________________________
My ranking
Most likely to last, 1, to least likely, 4. Write one reason for each rank.
| Rank | Garment | Reason |
|---|---|---|
| 1 | ||
| 2 | ||
| 3 | ||
| 4 |
Part 4. The trade-off: price now against cost over time
Two garments, two different people. Compute both.
Garment 2, the thin t-shirt: $8 [update]. Garment 1, the heavy sweatshirt: $44 [update].
Person 1: a student who walks to school and will wear it four days a week for two winters
About how many wears in two winters? ________ wears
| Garment | Price | Wears | Cost per wear |
|---|---|---|---|
| The $8 t-shirt | $8 | $ | |
| The $44 sweatshirt | $44 | $ |
Verdict, one sentence: ________________________________________________
Person 2: someone who needs a shirt for one concert
About how many wears? ________ wears
| Garment | Price | Wears | Cost per wear |
|---|---|---|---|
| The $8 t-shirt | $8 | $ | |
| The $44 sweatshirt | $44 | $ |
Verdict, one sentence: ________________________________________________
The point in your own words: cost per wear only answers the question once you know ________________________________.
Exit card
3 things you would check on a garment before buying it:
- ______________________ 2. ______________________ 3. ______________________
2 cost-per-wear numbers you computed today, with units:
$__________ per wear and $__________ per wear
1 item in your own closet that you now think was a good buy or a bad buy, and why, in six words:
Grade 8 stretch (optional, on the back)
- At what number of wears does the $44 sweatshirt become cheaper per wear than an $8 t-shirt worn 10 times? Show your work.
- The $8 t-shirt survives 10 washes. The $44 sweatshirt survives 100. If you need a sweatshirt for 100 washes, what does each option actually cost you in total? Which is cheaper?
- Pick a coat you own. Estimate its price and the wears per winter. What is its cost per wear per winter?
- * *
Teacher key
Part 1
(a) $60 ÷ 200 = $0.30 per wear.
(b) $15 ÷ 5 = $3.00 per wear.
(c) The estimate is the student's. At about 60 wears per winter: 3 × 60 = 180 wears, $90 ÷ 180 = $0.50 per wear. Accept any reasonable estimate between about 40 and 90 wears per winter with the division done correctly on the student's own number. A student who estimates 50 gets 150 wears and $0.60 per wear, which is also correct.
Most per wear: the $15 shirt at $3.00. Lowest price: the $15 shirt. The sentence should say something like "the cheapest thing to buy was the most expensive thing to own," or "price does not tell you what something costs you."
Watch for: dividing wears by price (200 ÷ 60 = 3.33 wears per dollar). Not wrong as a rate, but not the one a buyer compares. Say so and require dollars per wear.
Part 2
| Factor | A good one | A fail |
|---|---|---|
| Fiber | Cotton or a cotton-rich blend for comfort and durability; wool for warmth; a blend for wash durability; percentages printed | No label; "cotton blend" with no percentages; a garment that is mostly elastane in a place that takes stress |
| Seam type | Double-needle or flat felled on any seam that carries load | Single-needle on a load-bearing seam; a serged edge with no seam behind it |
| Stitches per inch | 10 to 12 | 8 or fewer |
| Reinforcement | Bar tacks at pocket corners and belt loops, a gusset under the arm, a doubled knee, a reinforced strap join | Nothing at any stress point, especially where a strap or pocket joins |
| Buttons and closures | Four to six passes of thread, a shank so the button sits above the fabric, a knot that holds; a zipper that runs smoothly both ways | A button held by two loose threads, no shank, a knot cut flush; a zipper that catches or separates |
Part 3
There is no single right answer; the answer depends on the four garments in the room. Score on process, not on outcome: did the student count stitches with the ruler on a structural seam, name a seam type, and find a real stress point. The intended ranking for the suggested set is (1) the jeans, (2) the heavy cotton sweatshirt, (3) the fast-fashion blouse, (4) the thin promotional t-shirt, but a student who ranks the sweatshirt first with good reasons is correct.
Part 4
Person 1, at four days a week for about 24 weeks of cold weather over two winters, roughly 190 to 200 wears. Accept any estimate in that range.
- $8 ÷ 200 = $0.04 per wear, but the thin t-shirt will not survive 200 wearings, which is the whole point; a student who says so in the verdict has the best answer.
- $44 ÷ 200 = $0.22 per wear.
- Verdict: the sweatshirt, because the t-shirt's $0.04 is a number that assumes something impossible.
Person 2, one concert, 1 to 3 wears.
- $8 ÷ 1 = $8.00 per wear. $44 ÷ 1 = $44.00 per wear.
- Verdict: the t-shirt, or better, borrow or wear something you own.
The point: cost per wear only answers the question once you know who is wearing it and how often.
Grade 8 stretch
- The $8 t-shirt worn 10 times is $0.80 per wear. The $44 sweatshirt beats $0.80 per wear at 44 ÷ 0.80 = 55 wears. So at 56 wears or more, the sweatshirt is cheaper per wear.
- For 100 washes: the t-shirt needs 10 shirts at $8 = $80. The sweatshirt is one at $44. The sweatshirt is cheaper by $36, and that is before counting the waste of nine discarded shirts, which is the Lesson 5.14 connection.
- Student's own numbers. Check the division and the unit.