Solved Exercises on Temperature Problems in Grade 2

Master temperature measurement: reading thermometers, comparing temperatures, temperature changes, and basic temperature operations through these 5 detailed exercises.

Solution: Exercises 1 to 3
1 Reading Thermometers
Exercise 1
Look at the thermometer and tell what temperature it shows.
Temperature: ? °F
Definition:

Thermometer: A tool that measures how hot or cold something is. Temperature is measured in degrees (°F or °C).

Reading Method:
  1. Look at the red mercury line inside the thermometer
  2. Find where the red line ends
  3. Read the number next to that point
  4. Count the small lines between numbers to get exact temperature
Step 1: Identify the mercury level

The red mercury line reaches up to the 72°F mark on our thermometer

Step 2: Read the temperature

Each big line represents 10 degrees. The small lines between represent 2 degrees each.

Step 3: Determine the final temperature

The mercury stops at the second small line after 70°F, so it's 72°F

The temperature is 72°F
Final answer:

The thermometer shows 72°F

Applied rules:

• Mercury reading: Always read from the top of the red mercury line

• Scale interpretation: Count by tens for big marks, by twos for small marks

• Accuracy: Estimate between marks if needed

Tip 1: Always look straight at the thermometer to avoid parallax error.
Tip 2: Remember: higher mercury level = hotter temperature.
2 Comparing Temperatures
Exercise 2
Today it's 45°F. Yesterday it was 38°F. Which day was warmer?
Definition:

Temperature Comparison: Using greater than (>), less than (<), or equal (=) to compare temperatures.

Step 1: Write down the temperatures

Today: 45°F, Yesterday: 38°F

Step 2: Compare the numbers

45 is greater than 38, so 45°F > 38°F

Step 3: Interpret the result

If the temperature is higher, it means it's warmer

Today
45°F
>
Yesterday
38°F
Today (45°F) is warmer than yesterday (38°F)
Final answer:

Today was warmer because 45°F > 38°F

Applied rules:

• Number comparison: Higher numbers mean higher temperatures

• Symbol usage: > means greater than, < means less than

• Context understanding: Higher temperature = warmer

Tip 1: Use a number line to visualize temperature comparisons.
Tip 2: Remember: higher number = warmer temperature.
3 Temperature Change
Exercise 3
In the morning it was 52°F. At noon it became 68°F. How much did the temperature rise?
Definition:

Temperature Change: The difference between starting and ending temperatures. Add when warming up, subtract when cooling down.

Step 1: Identify starting and ending temperatures

Starting: 52°F, Ending: 68°F

Step 2: Determine if it increased or decreased

68°F is greater than 52°F, so it increased (rose)

Step 3: Calculate the difference

68 - 52 = 16°F

Morning
52°F
+
Rose by
16°F
=
Noon
68°F
The temperature rose by 16°F
Final answer:

The temperature rose by 16°F

Applied rules:

• Subtraction rule: To find change, subtract the smaller from the larger

• Direction: Rising = addition, Falling = subtraction

• Units: Always include degree units in your answer

Tip 1: Draw a number line to visualize the temperature change.
Tip 2: Remember: "rise" means increase, "fall" means decrease.
Temperature Rules and Methods
Temperature Change = Final Temp - Initial Temp
Temperature Calculation Formula
Key definitions:

Temperature: How hot or cold something is

Thermometer: Tool that measures temperature

Degree (°): Unit used to measure temperature

Fahrenheit (°F): Temperature scale used in the US

Complete methodology:
  1. Reading thermometers: Look at the mercury level and match to scale
  2. Comparing temperatures: Use >, <, or = symbols
  3. Calculating changes: Subtract initial from final temperature
  4. Understanding context: Relate temperature to weather conditions
Tip 1: Water freezes at 32°F and boils at 212°F.
Tip 2: Room temperature is usually around 70°F.
Tip 3: The bigger the number, the warmer it is.
Tip 4: Always include the degree symbol (°) and unit (F).
Common errors: Forgetting the degree symbol, misreading the scale, confusing higher/lower temperatures.
Weather connections: 30s°F = Cold winter, 40s°F = Cool fall/spring, 50s°F = Mild spring/fall, 60s°F = Warm fall/spring, 70s°F = Comfortable summer, 80s°F+ = Hot summer.
Temperature facts to remember:

• Freezing point of water: 32°F

• Boiling point of water: 212°F

• Comfortable room temperature: ~70°F

• Body temperature: ~98.6°F

• Temperature change formula: Final - Initial = Change

Solution: Exercises 4 to 5
4 Temperature Differences
Exercise 4
The temperature at sunrise was 35°F. At sunset it was 58°F. What was the temperature difference?
Definition:

Temperature Difference: The amount between two temperatures, found by subtraction.

Step 1: Identify both temperatures

Sunrise: 35°F, Sunset: 58°F

Step 2: Determine which is larger

58°F is larger than 35°F

Step 3: Subtract to find the difference

58 - 35 = 23°F

Sunset
58°F
-
Sunrise
35°F
=
Difference
23°F
Step 4: Verify the result

35°F + 23°F = 58°F ✓

The temperature difference is 23°F
Final answer:

The temperature difference was 23°F

Applied rules:

• Subtraction principle: Always subtract the smaller number from the larger

• Difference calculation: The result shows how far apart the temperatures are

• Verification: Add the difference back to check accuracy

Tip 1: The difference is always positive, regardless of which temperature is larger.
Tip 2: You can also think of it as: "How many degrees did it change?"
5 Ordering Temperatures
Exercise 5
Order these temperatures from coldest to warmest: 28°F, 45°F, 32°F, 50°F, 15°F
Definition:

Ordering temperatures: Arranging temperatures from lowest to highest (or vice versa) based on numerical value.

Step 1: List all temperatures

28°F, 45°F, 32°F, 50°F, 15°F

Step 2: Compare each number

15, 28, 32, 45, 50 (ignoring the degree symbol temporarily)

Step 3: Arrange from smallest to largest

15°F, 28°F, 32°F, 45°F, 50°F

Coldest
15°F
<
28°F
<
32°F
<
45°F
<
Warmest
50°F
Step 4: Verify the order

15 < 28 < 32 < 45 < 50, so the order is correct

From coldest to warmest: 15°F, 28°F, 32°F, 45°F, 50°F
Final answer:

15°F, 28°F, 32°F, 45°F, 50°F

Applied rules:

• Ascending order: Numbers arranged from smallest to largest

• Numerical comparison: Focus on the numbers, not the degree symbols

• Consistency: All temperatures must be in the same unit for comparison

Tip 1: Think of a number line to visualize the order.
Tip 2: Smaller numbers = colder temperatures.
Temperature Laws, Methods, Rules, and Definitions
Final Temp = Initial Temp + Change
Temperature Change Formula
Key definitions:

Temperature: A measure of how hot or cold something is

Thermometer: Instrument used to measure temperature

Degree (°): Unit of measurement for temperature

Fahrenheit (°F): Temperature scale commonly used in the United States

Celsius (°C): Temperature scale used in most countries worldwide

Complete methodology:
  1. Reading thermometers: Identify the scale, locate the mercury level, read the corresponding value
  2. Comparing temperatures: Compare numerical values using inequality symbols
  3. Calculating changes: Subtract initial from final temperature (or vice versa for decreases)
  4. Ordering temperatures: Arrange from lowest to highest based on numerical value
  5. Problem solving: Identify what's being asked and apply appropriate operation
Tip 1: Always read thermometers at eye level to avoid errors.
Tip 2: Remember: higher numbers = warmer temperatures.
Tip 3: For temperature differences, always subtract the smaller from the larger.
Tip 4: Check your work by adding the difference back to the original.
Common errors: Misreading thermometer scales, confusing higher/lower temperatures, forgetting to include degree symbols.
Key benchmarks: Water freezes at 32°F, room temp ≈ 70°F, normal body temp ≈ 98.6°F, water boils at 212°F.
Temperature formulas to remember:

• Temperature change: Final - Initial = Change

• Finding final temperature: Initial + Change = Final

• Finding initial temperature: Final - Change = Initial

• Comparing: Use >, <, or = symbols

• Ordering: Arrange from lowest to highest numerical value

Questions & Answers

Question: I don't understand why 50°F is warmer than 30°F. Aren't bigger numbers supposed to be colder since ice is frozen?

Answer: That's a great question! The confusion comes from mixing up freezing with the number system. Let me explain:

  • Yes, 32°F is the freezing point of water, but that doesn't make it cold everywhere on the scale
  • Think of a number line: 50 is to the right of 30, so it's bigger
  • On the temperature scale, higher numbers always mean warmer temperatures
  • So 50°F is definitely warmer than 30°F (even though both are relatively cool compared to room temperature)

Think of it this way: if you were counting toys, 50 toys would be more than 30 toys. Similarly, 50°F has more heat energy than 30°F, making it warmer.

Example: If it's 30°F outside, you'd need a heavy coat. If it's 50°F, you might only need a light jacket. The higher number means more warmth!

Question: My child gets confused when reading thermometers. The mercury line seems to be between two numbers. How should they handle this?

Answer: This is very common! Here's a systematic approach to help your child:

  • Estimation method: If the mercury is halfway between 40°F and 42°F, it's approximately 41°F
  • Look for smaller markings: Many thermometers have small lines representing 1 or 2 degree increments between the larger numbers
  • Practice with known temperatures: Show them that room temperature is around 70°F and body temperature is around 98°F
  • Use a magnifying glass: Sometimes this helps see the exact position more clearly

Tell your child: "If it's closer to one number than the other, round to that number. If it's right in the middle, pick the number in between."

For example, if mercury is slightly above 45°F but below 46°F, they could estimate 45.5°F or just say "about 45°F" for simplicity.

Question: Why do we sometimes say "degrees" and sometimes just "F"? What's the difference between Fahrenheit and Celsius?

Answer: Great observation! Let me break this down:

  • Degrees (°): This is the symbol we use for temperature measurements in general
  • Fahrenheit (°F): The temperature scale used mostly in the United States
  • Celsius (°C): The temperature scale used in most other countries
  • The difference: They have different reference points - water freezes at 32°F vs 0°C, and boils at 212°F vs 100°C

Think of it like different languages - both measure temperature, but use different numbers. In school, we often just say "degrees" followed by F or C to show which system we're using.

Fun fact: In Fahrenheit, the scale was designed so that normal human body temperature would be around 100°F (though it's actually about 98.6°F). Celsius was designed with water's freezing and boiling points as 0° and 100°.