Identifying Independent and Dependent Variables Worksheet | PDF - Free Printable

It looks like you've uploaded a document with several science experiment scenarios, and you're being asked to identify the Independent Variable (IV), Dependent Variable (DV), and Constants in each scenario. Let's go through each one step by step.

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5. Jessica wanted to see which kitchen cleaner worked best for cleaning her counters. She used: Dawn, Clorox, and just water. For each cleaner, she put 5 milliliters of grape juice on the counter, sprayed the cleaner, and wiped it with one paper towel.

- Independent Variable (IV): The type of cleaner used (Dawn, Clorox, water)
→ This is what Jessica is changing to test the effect.

- Dependent Variable (DV): How well the counter was cleaned (how much grape juice remained or how clean it looked)
→ This is what is being measured or observed.

- Constants: Amount of grape juice (5 mL), method of application (spray + wipe), type of paper towel, surface area tested, amount of pressure applied when wiping, etc.
→ These are kept the same to ensure fair testing.

✔ Answer:
- IV: Type of cleaner
- DV: Cleanliness of counter
- Constants: Amount of grape juice, wiping method, paper towel, etc.

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6. Evan wanted to find out what toothpaste made teeth the cleanest. Everyday he brushed his teeth with a different product and then took a plaque test to see how much plaque was left. He used Crest, Colgate, Close-up, and water.

- Independent Variable (IV): Type of toothpaste used (Crest, Colgate, Close-up, water)
→ What is being changed.

- Dependent Variable (DV): Amount of plaque left after brushing
→ What is being measured.

- Constants: Brushing time, brushing technique, amount of toothpaste used, frequency of brushing, diet, mouthwash use (if any), time between meals, etc.
→ All factors that should be held constant to isolate the effect of toothpaste.

✔ Answer:
- IV: Type of toothpaste
- DV: Amount of plaque remaining
- Constants: Brushing method, time, frequency, etc.

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7. Angelique wanted to find out what shampoo made her hair the shiniest. Everyday she washed her hair with different shampoos and then rated how shiny her hair was, on a scale from 1–10. She used Pantene, Herbal Essences, L’Oreal, and just water.

- Independent Variable (IV): Type of shampoo used (Pantene, Herbal Essences, L’Oreal, water)
→ What’s being tested.

- Dependent Variable (DV): Shiness of hair (rated on a 1–10 scale)
→ What’s being measured.

- Constants: Water temperature, amount of shampoo, washing technique, drying method, hair length, hair type, frequency of washing, styling products used, etc.
→ These must stay the same to keep the test fair.

✔ Answer:
- IV: Type of shampoo
- DV: Hair shininess (rating)
- Constants: Washing method, water temp, drying, etc.

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8. Harrison wanted to find out what soil works best for growing roses. He grew them in potting soil, clay, sand, and loam and found out how tall they grew. After one week, he measured their height and how many leaves they had.

- Independent Variable (IV): Type of soil (potting soil, clay, sand, loam)
→ What’s being changed.

- Dependent Variable (DV): Height of the plant and number of leaves
→ What’s being measured (both are outcomes).

- Constants: Amount of sunlight, watering schedule, amount of water given, size of pots, rose variety, planting depth, temperature, etc.
→ These should remain the same across all plants.

✔ Answer:
- IV: Type of soil
- DV: Plant height and number of leaves
- Constants: Light, water, pot size, plant type, etc.

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9. Emily wanted to see what battery lasted the longest. She put each battery into a clock and recorded the time that the clock stopped. She used Duracell, Energizer, Kroger brand, and EverReady.

- Independent Variable (IV): Brand of battery (Duracell, Energizer, Kroger, EverReady)
→ What’s being tested.

- Dependent Variable (DV): How long the clock ran (time until it stopped)
→ What’s being measured.

- Constants: Type of clock, voltage requirements, room temperature, usage pattern, initial charge, etc.
→ All clocks must be identical and used under the same conditions.

✔ Answer:
- IV: Battery brand
- DV: Duration the clock ran
- Constants: Clock model, environment, usage, etc.

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✔ Final Answers:

| Question | Independent Variable (IV) | Dependent Variable (DV) | Constants |
|--------|----------------------------|--------------------------|-----------|
| 5 | Type of cleaner | Cleanliness of counter | Grape juice amount, wiping method, paper towel, etc. |
| 6 | Type of toothpaste | Amount of plaque remaining | Brushing method, time, frequency, etc. |
| 7 | Type of shampoo | Hair shininess rating | Washing method, water temp, drying, etc. |
| 8 | Type of soil | Plant height and number of leaves | Sunlight, water, pot size, plant type, etc. |
| 9 | Battery brand | Time until clock stops | Clock type, environment, usage, etc. |

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