Lesson Notes By Weeks and Term v5 - Grade 5

Lesson Video

This page supports the lesson note with a companion video and a short classroom-ready summary.

For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.

Performance objectives

• Convert between units of time and solve problems with elapsed time.
• Read temperature in degrees Celsius and solve problems with temperature changes.
• Solve practical problems involving length, mass, and volume.
• Estimate and measure everyday objects using appropriate tools.

Lesson summary

This week, we'll be focusing on time, temperature, and everyday measurement problems. These are essential skills that we use every day in South Africa, from cooking meals and planning school activities to understanding weather forecasts and buying groceries. Mastering these concepts will help you become more independent and confident in dealing with real-world situations. For example, knowing how to convert cooking times for pap or how to calculate the distance to the nearest spaza shop can make a big difference in your daily life.

Lesson notes

2.1 Time: Units of Time: The standard units of time are seconds (s), minutes (min), hours (h), days, weeks, months, and years. 1 minute = 60 seconds 1 hour = 60 minutes 1 day = 24 hours 1 week = 7 days Analogue Clocks: Analogue clocks have a face with numbers 1-12 and two hands: a short hour hand and a long minute hand. The second hand is usually thinner and moves quickly. The hour hand indicates the hour. The minute hand indicates the minutes past the hour. To read the time, first, identify the hour and then count the minutes past the hour.

Digital Clocks: Digital clocks display the time numerically (e.g., 14:30).

The format is usually hours:minutes. In 24-hour format, 1 PM is 13:00, 2 PM is 14:00, and so on.

Elapsed Time: Elapsed time is the amount of time that passes between two points in time. To calculate elapsed time, you can count forward from the start time to the end time.

Example 1: What time will it be 3 hours and 15 minutes after 9:00 AM? 3 hours after 9:00 AM is 12:00 PM. 15 minutes after 12:00 PM is 12:15 P

M. Therefore, the time will be 12:15 P

M. Example 2: How long does it take to travel from Johannesburg to Durban if the bus leaves Johannesburg at 6:00 PM and arrives in Durban at 6:00 AM the next day?

From 6:00 PM to 6:00 AM is 12 hours.

Therefore, the journey takes 12 hours. 2.2 Temperature: Units of Temperature: In South Africa, we use degrees Celsius (°C) to measure temperature.

Thermometers: Thermometers are used to measure temperature. They have a scale with markings representing different temperatures. You read the temperature by noting the level of the liquid (usually red or blue) in the thermometer.

Understanding Temperature Changes: Increasing temperature indicates that something is getting hotter. Decreasing temperature indicates that something is getting colder.

Example 1: The temperature in Cape Town is 25°C in the afternoon and drops to 18°C at night. How much did the temperature drop? Temperature drop = 25°C - 18°C = 7°

C. Therefore, the temperature dropped by 7°

C. Example 2: The temperature in Upington is 35°C. If it increases by 5°C, what will the new temperature be? New temperature = 35°C + 5°C = 40°

C. Therefore, the new temperature will be 40°C. 2.3 Everyday Measurement Problems: Length: We use meters (m) and centimeters (cm) to measure length. 1 meter = 100 centimeters Mass: We use kilograms (kg) and grams (g) to measure mass (how heavy something is). 1 kilogram = 1000 grams Volume: We use liters (L) and milliliters (mL) to measure volume (how much space something occupies). 1 liter = 1000 milliliters Solving Problems: When solving measurement problems, ensure that all measurements are in the same units.

Example 1: A table is 2 meters long. A cloth is 150 centimeters long. How much longer is the table than the cloth?

Convert meters to centimeters: 2 meters = 2 x 100 = 200 centimeters. Difference = 200 cm - 150 cm = 50 cm.

Therefore, the table is 50 cm longer than the cloth.

Example 2: A bag of mealie meal weighs 2.5 kg. How many grams does it weigh?

Convert kilograms to grams: 2.5 kg = 2.5 x 1000 = 2500 grams.

Therefore, the bag weighs 2500 grams.

Example 3: A bottle contains 1.5 liters of water. How many milliliters of water does it contain?

Convert liters to milliliters: 1.5 liters = 1.5 x 1000 = 1500 milliliters.

Therefore, the bottle contains 1500 milliliters of water. Guided Practice (With Solutions)

Question 1: A soccer match starts at 3:15 PM and lasts for 90 minutes. What time does the match end?

Solution: 90 minutes = 1 hour and 30 minutes. 1 hour after 3:15 PM is 4:15 PM. 30 minutes after 4:15 PM is 4:45 P

M. The match ends at 4:45 P

M. Commentary:* We converted minutes to hours and minutes to make the addition easier.

Question 2: The temperature in Johannesburg is 12°C in the morning. It rises by 8°C during the day. What is the temperature in the afternoon?

Solution: Afternoon temperature = 12°C + 8°C = 20°

C. The temperature in the afternoon is 20°

C. Commentary:* This is a straightforward addition problem.

Question 3: A piece of string is 3 meters long. You cut off 80 cm. How much string is left?

Solution: Convert meters to centimeters: 3 meters = 3 x 100 = 300 cm. Length of string left = 300 cm - 80 cm = 220 cm.

Therefore, 220 cm of string is left.

Commentary:* It's crucial to convert to the same units before subtracting.

Question 4: A jug contains 2 liters of orange juice. You pour out 750 ml. How much orange juice is left in the jug?

Solution: Convert liters to milliliters: 2 liters = 2 x 1000 = 2000 ml. Amount of juice left = 2000 ml - 750 ml = 1250 ml.

Therefore, 1250 ml of orange juice is left.

Commentary:* Again, ensure you're working with the same units (milliliters). Independent Practice (Questions Only)

A taxi leaves Pretoria at 7:45 AM and arrives in Johannesburg at 8:30 AM. How long did the journey take? The temperature in Durban is 28°C. In Bloemfontein, it is 15°C. What is the difference in temperature? A roll of fabric is 10 meters long. Mrs.