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Time and Calendar - Reading Time to the nearest 5 minutes

Grade 3ICSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

The clock face is a circular dial numbered from 11 to 1212. Between any two consecutive numbers, there are 55 smaller minute divisions. To read the time to the nearest 55 minutes, we count the gaps between numbers by 5s5s.

The clock has two main hands: the shorter hand is the Hour Hand and the longer hand is the Minute Hand. The hour hand tells us the hour, and the minute hand tells us how many minutes have passed since that hour started.

To find the minutes, look at the number the long minute hand is pointing to and multiply that number by 55. For example, if the minute hand points to 44, the minutes are 4×5=204 \times 5 = 20. Visually, you can imagine jumping around the clock: 55 at 11, 1010 at 22, 1515 at 33, and so on.

When the minute hand points to 33, it is called Quarter Past. This represents 1515 minutes. Visually, the minute hand has moved one-fourth of the way around the clock face.

When the minute hand points to 66, it is called Half Past. This represents 3030 minutes. At this point, the minute hand has traveled halfway around the circle, and the hour hand will be exactly halfway between two numbers.

When the minute hand points to 99, it is called Quarter To. This represents 4545 minutes past the current hour or 1515 minutes remaining until the next hour. Visually, the minute hand has completed three-quarters of its journey around the clock.

The hour hand moves slowly as the minute hand moves. If the hour hand is between two numbers, such as 88 and 99, we always read the smaller number (88) as the hour, because it has passed 88 but hasn't reached 99 yet.

Time is written in the digital format as HH:MMHH:MM. The first part (HHHH) represents the hour, and the second part (MMMM) represents the minutes. A colon (::) is used to separate them.

📐Formulae

1 hour=60 minutes1 \text{ hour} = 60 \text{ minutes}

Minutes=Number pointed to by Minute Hand×5\text{Minutes} = \text{Number pointed to by Minute Hand} \times 5

Half past H=H:30\text{Half past } H = H:30

Quarter past H=H:15\text{Quarter past } H = H:15

Quarter to H=(H1):45\text{Quarter to } H = (H-1):45

💡Examples

Problem 1:

Determine the time when the hour hand is between 1010 and 1111, and the minute hand is pointing exactly at 88.

Solution:

  1. Identify the hour: The hour hand is between 1010 and 1111, so the hour is 1010.
  2. Calculate the minutes: The minute hand is at 88. Multiply the number by 55: 8×5=408 \times 5 = 40 minutes.
  3. Combine: The time is 10:4010:40.

Explanation:

Since the hour hand hasn't reached 1111 yet, the hour remains 1010. We use the 55-times table for the minute hand position (88) to find the minutes.

Problem 2:

Write the digital time for 'Quarter to 33'.

Solution:

  1. Understand 'Quarter to': This means 1515 minutes are left before the next hour.
  2. Minutes: 'Quarter to' always means the minute hand is at 99, so 9×5=459 \times 5 = 45 minutes.
  3. Hour: Since it is 'to 33', it is not 33 o'clock yet. The current hour is 22.
  4. Result: The time is 2:452:45.

Explanation:

In 'Quarter to' expressions, the digital hour is always one less than the hour mentioned, and the minutes are always 4545.