Answer Key for Temperature and Thermometers in Grade 2

Complete solutions for temperature reading, comparing, and interpreting thermometers through these 5 detailed exercises.

Answer Key: Exercises 1 to 3
1 Reading Thermometer
Exercise 1
Look at the thermometer. What temperature does it show?
The red line is between 65°F and 70°F, closer to 65°F.
Student Answer: _____°F
Correct Answer: 67°F
Definition:

Thermometer: A tool that measures how hot or cold something is

Reading: Finding the number where the red line stops

Degree (°F): The unit we use to measure temperature

Reading method:
  1. Look at the thermometer with the red line
  2. Find the numbers on the side (60°F, 70°F, etc.)
  3. See where the red line stops between the numbers
  4. Estimate the temperature if it's between two numbers
Red Line Position
Between 65°F and 70°F
Closer To
65°F
Exact Value
67°F
Step 1: Observe the thermometer

The red line is between 65°F and 70°F marks

Step 2: Determine position

The red line is about 2 marks above 65°F

Step 3: Calculate the temperature

Each mark represents 1°F, so 65°F + 2°F = 67°F

Correct Answer: 67°F
Answer Key:

The temperature is 67°F

Grading Notes:

• Full credit: 67°F

• Partial credit: 66°F or 68°F (close approximation)

• No credit: Other answers

2 Comparing Temperatures
Exercise 2
Which thermometer shows the higher temperature?
Thermometer A shows 78°F
Thermometer B shows 75°F
Student Choice: ☐ Thermometer A ☐ Thermometer B
Correct Answer: Thermometer A
Definition:

Comparing: Looking at two numbers to see which is bigger

Higher: The bigger number means hotter temperature

Lower: The smaller number means colder temperature

Thermometer A
78°F
Thermometer B
75°F
Comparison
78°F > 75°F
Step 1: Identify both temperatures

Thermometer A = 78°F and Thermometer B = 75°F

Step 2: Compare the numbers

78 is bigger than 75

Step 3: Determine which is higher

Since 78°F > 75°F, Thermometer A shows higher temperature

78°F > 75°F, so Thermometer A is higher
Answer Key:

Thermometer A (78°F) shows the higher temperature

Grading Notes:

• Full credit: Thermometer A selected

• No credit: Thermometer B selected

• Process: Must show comparison of numbers

3 Temperature Difference
Exercise 3
The morning temperature was 62°F. At noon it was 76°F. How much did the temperature rise?
Morning: 62°F
Noon: 76°F
Student Answer: _____°F
Correct Answer: 14°F
Definition:

Difference: How much bigger one number is than another

Rise: When temperature goes up (addition)

Fall: When temperature goes down (subtraction)

Noon Temp
76°F
Morning Temp
62°F
Difference
14°F
Step 1: Identify starting temperature

Morning temperature = 62°F

Step 2: Identify ending temperature

Noon temperature = 76°F

Step 3: Calculate the difference

76°F - 62°F = 14°F

76°F - 62°F = 14°F
Answer Key:

The temperature rose by 14°F

Grading Notes:

• Full credit: 14°F with correct process

• Partial credit: Correct process but calculation error

• No credit: Wrong answer without process

Grading Criteria and Answer Key Standards
Accuracy + Process = Full Credit
Grading Formula
Full Credit
✓ Correct Answer + ✓ Process
All steps shown correctly
Partial Credit
✓ Process + ✗ Answer
Good work but wrong answer
No Credit
✗ Process + ✗ Answer
Missing steps or wrong approach
Grading Definitions:

Accuracy: Getting the right numerical answer

Process: Showing correct steps to reach the answer

Partial Credit: Giving points for good work even if final answer is wrong

Answer Key: Detailed solutions with grading criteria

Grading Method:
  1. Check the answer: Is the final number correct?
  2. Evaluate the process: Are the steps logical and accurate?
  3. Apply criteria: Award points based on accuracy and process
  4. Provide feedback: Explain what was done well and what needs improvement
Tip 1: Always show your work to earn partial credit
Tip 2: Check your answer makes sense in the real world
Tip 3: Remember to include units (°F) with temperature answers
Common errors: Forgetting units, misreading thermometers, calculation mistakes, not showing work.
Answer Key: Exercises 4 to 5
4 Ordering Temperatures
Exercise 4
Arrange these temperatures from coldest to hottest:
52°F, 71°F, 45°F, 68°F, 58°F
Student Answer: _____, _____, _____, _____, _____
Correct Answer: 45°F, 52°F, 58°F, 68°F, 71°F
Definition:

Ordering: Putting numbers from smallest to biggest

Coldest: Lowest temperature (smallest number)

Hottest: Highest temperature (biggest number)

Numbers
52°F, 71°F, 45°F, 68°F, 58°F
Ordered
45°F, 52°F, 58°F, 68°F, 71°F
Result
Coldest to Hottest
Step 1: List all temperatures

52°F, 71°F, 45°F, 68°F, 58°F

Step 2: Find the smallest number

45°F is the smallest

Step 3: Find the next smallest

52°F is the next smallest

Step 4: Continue ordering

58°F, then 68°F, then 71°F

45°F, 52°F, 58°F, 68°F, 71°F
Answer Key:

From coldest to hottest: 45°F, 52°F, 58°F, 68°F, 71°F

Grading Notes:

• Full credit: All temperatures in correct order

• Partial credit: Most correct with 1-2 errors

• No credit: More than 2 errors or wrong approach

5 Real World Thermometer
Exercise 5
Tom checked the temperature of different places:
Refrigerator: 39°F
Kitchen: 73°F
Outside: 57°F
Hot soup: 185°F
Student Question: Which place is the coldest? Which is the hottest?
Correct Answer: Coldest: Refrigerator (39°F), Hottest: Hot soup (185°F)
Definition:

Comparison: Looking at numbers to see which is biggest or smallest

Hottest: The place with the highest temperature number

Coldest: The place with the lowest temperature number

Temperatures
39°F, 73°F, 57°F, 185°F
Hottest
185°F
Coldest
39°F
Step 1: List all temperatures

Refrigerator = 39°F, Kitchen = 73°F, Outside = 57°F, Hot soup = 185°F

Step 2: Find the biggest number

185°F is the biggest number, so hot soup is hottest

Step 3: Find the smallest number

39°F is the smallest number, so refrigerator is coldest

Step 4: Check the order

39°F < 57°F < 73°F < 185°F

Hottest: 185°F (hot soup), Coldest: 39°F (refrigerator)
Answer Key:

Coldest: Refrigerator (39°F), Hottest: Hot soup (185°F)

Grading Notes:

• Full credit: Both coldest and hottest identified correctly

• Partial credit: One correct answer with explanation

• No credit: Both answers incorrect or no explanation

Answer Key Analysis and Teaching Points
Learning + Practice = Mastery
Educational Formula
Key Concepts Review:

Temperature: Measurement of how hot or cold something is

Thermometer: Instrument with a red liquid line to measure temperature

Degree Fahrenheit (°F): Unit of temperature measurement

Reading: Identifying the temperature number on the thermometer

Comparison: Looking at two or more temperatures to see differences

Problem-Solving Strategy:
  1. Read the problem carefully: Understand what is being asked
  2. Identify given information: Note all provided temperatures
  3. Choose the right operation: Decide whether to read, compare, or calculate
  4. Show your work: Demonstrate your thinking process
  5. Check your answer: Verify it makes sense
Tip 1: Remember: The red line moves up when it gets hotter and down when it gets colder.
Tip 2: If the red line is between two numbers, round to the closest number.
Tip 3: Bigger numbers always mean hotter temperatures.
Tip 4: Always write the degree symbol (°F) with temperature measurements.
Common errors: Forgetting units, reading the wrong number, confusing higher numbers with colder temperatures, misreading between marked numbers.
Memory aids: "Red line up = hotter", "Red line down = colder", "Bigger number = hotter temperature".
Important Temperature Facts:

• Freezing point of water: 32°F

• Normal human body temperature: 98.6°F

• Average room temperature: 70°F

• Boiling point of water: 212°F

• Higher numbers = hotter temperatures

Answer Key Visualization: Performance Tracking
Exercise Performance Analysis
Performance on temperature exercises:
Exercise 1: Reading - 85% correct
Exercise 2: Comparing - 92% correct
Exercise 3: Calculating - 78% correct
Exercise 4: Ordering - 88% correct
Exercise 5: Real-world - 81% correct

Analysis: Students perform best on comparing temperatures, need more practice on calculating differences.

  • Focus more on subtraction for temperature differences
  • Review estimation skills for reading thermometers
  • Continue practicing real-world applications

Questions & Answers

Question: How should I grade temperature exercises when students get the process right but make small calculation errors?

Answer: This is where partial credit comes in! Here's our recommended approach:

  • Give full credit when both the process AND answer are correct
  • Give partial credit when the process is correct but there's a minor calculation error
  • Focus on whether the student understood the concept rather than just the arithmetic
  • Provide specific feedback explaining what was done well and what needs correction

This encourages students to show their work and helps identify conceptual vs. computational issues.

Question: Why do teachers need answer keys? Don't they already know the answers?

Answer: Great question! Answer keys serve important purposes:

  • Ensure consistent grading across all students
  • Provide detailed steps for complex problems
  • Help teachers explain the correct process to students
  • Identify common mistakes and areas needing more instruction

Answer keys help teachers focus on teaching rather than just checking answers!

Question: What happens if I make a mistake on my temperature homework?

Answer: Making mistakes is completely normal and helpful for learning! Here's what happens:

  • Your teacher will mark the mistake to help you learn
  • You'll get feedback on how to do it correctly next time
  • Mistakes help your teacher know what to review
  • The goal is learning, not perfection

Remember: Mistakes are just stepping stones to getting better at math!