Step-by-step Maths Level 4 Time to the minute: check-up and practice test questions

Method. Convert between the 12-hour and 24-hour clock. The minutes stay the same.

1. Note the time of day. a.m. is the morning. p.m. is the afternoon.
   p.m.
2. Change the hour. For p.m., add 12 to the hour unless it is 12. 12 a.m. is 00.
   1 gives 13
3. Write the time. Use two digits for the hour.
   13:38

Check. Check: 13:38 is the same time of day as 1:38 p.m..

Watch out. The minutes never change. Only the hour changes on the 24-hour clock.

Method. There are 60 minutes in an hour. Multiply hours by 60 to change to minutes, or divide minutes by 60 to change to hours.

1. Count how many whole hours there are. Every 60 minutes is 1 hour.
   87 ÷ 60 = 1 remainder 27
2. Find the minutes left over. The remainder is the extra minutes.
   87 - 60 = 27
3. Write the answer. Say the hours, then the minutes.
   1 hour 27 minutes

Check. Check: 1 hour is 60 minutes, and 27 more is 87.

Watch out. Do not write 2 hours 135 minutes. Change every 60 minutes into 1 hour.

Method. Convert between the 12-hour and 24-hour clock. The minutes stay the same.

1. Find the hour on a 12-hour clock. Subtract 12 from the hour if it is after 12. Midnight and noon are 12.
   18 is 6 on a 12-hour clock
2. Decide a.m. or p.m. Times before 12:00 are a.m. and times from 12:00 are p.m.
   p.m.
3. Write the time. Write the hour, the minutes, then a.m. or p.m.
   6:55 p.m.

Check. Check: 6:55 p.m. is the same time of day as 6:55 p.m..

Watch out. The minutes never change. Only the hour changes on the 24-hour clock.

Method. Count on from the start time to the end time, in steps: minutes to the next hour, whole hours, then minutes.

1. Count the minutes to the next hour, 18:00. Count on to the next full hour.
   17:07 to 18:00 is 53 minutes
2. Count the whole hours up to 17:00. Each full hour is 60 minutes.
   -1 hours = -60 minutes
3. Count the minutes from 17:00 to 17:30. Count on the last minutes.
   30 minutes
4. Add the parts. Add the minutes from each part.
   53 + -60 + 30 = 23
5. Write the duration. Give the answer in hours and minutes.
   23 minutes

Check. Check: 17:07 plus 23 minutes is 17:30.

Watch out. Count the minutes to the next hour first. Do not subtract the hours and the minutes separately.

Method. Count on from the start time to the end time, in steps: minutes to the next hour, whole hours, then minutes.

1. Count the minutes to the next hour, 13:00. Count on to the next full hour.
   12:30 to 13:00 is 30 minutes
2. Count the whole hours up to 12:00. Each full hour is 60 minutes.
   -1 hours = -60 minutes
3. Count the minutes from 12:00 to 12:50. Count on the last minutes.
   50 minutes
4. Add the parts. Add the minutes from each part.
   30 + -60 + 50 = 20
5. Write the duration. Give the answer in hours and minutes.
   20 minutes

Check. Check: 12:30 plus 20 minutes is 12:50.

Watch out. Count the minutes to the next hour first. Do not subtract the hours and the minutes separately.

Method. There are 60 minutes in an hour. Multiply hours by 60 to change to minutes, or divide minutes by 60 to change to hours.

1. Count how many whole hours there are. Every 60 minutes is 1 hour.
   77 ÷ 60 = 1 remainder 17
2. Find the minutes left over. The remainder is the extra minutes.
   77 - 60 = 17
3. Write the answer. Say the hours, then the minutes.
   1 hour 17 minutes

Check. Check: 1 hour is 60 minutes, and 17 more is 77.

Watch out. Do not write 2 hours 135 minutes. Change every 60 minutes into 1 hour.

Method. Convert between the 12-hour and 24-hour clock. The minutes stay the same.

1. Note the time of day. a.m. is the morning. p.m. is the afternoon.
   a.m.
2. Change the hour. For p.m., add 12 to the hour unless it is 12. 12 a.m. is 00.
   7 gives 07
3. Write the time. Use two digits for the hour.
   07:21

Check. Check: 07:21 is the same time of day as 7:21 a.m..

Watch out. The minutes never change. Only the hour changes on the 24-hour clock.

Method. Add the length of the activity to the start time. Carry extra minutes into the hours.

1. Write the start time. It is where we begin.
   14:28
2. Add the duration. Add 1 hour 45 minutes to the start time.
   14:28 + 1 hour 45 minutes = 16:13
3. Write the finish time. Use two digits for the hour and minutes.
   16:13

Check. Check: 1 hour 45 minutes before 16:13 is 14:28.

Watch out. When the minutes go past 60, add one hour and take away 60 minutes.

Method. Use the facts: 60 minutes in an hour, 24 hours in a day, and the number of days in each month.

1. Remember how many hours there are in 1 day. There are 24 hours in 1 day.
   1 day = 24 hours
2. Multiply by 2. There are 2 days.
   2 × 24 = 48
3. Write the answer. This is the total number of hours.
   48

Check. Check the fact: 60 minutes, 24 hours, or the days in the month.

Watch out. Learn the months with 30 days: April, June, September and November. All the others have 31 days, except February.

Method. Read the minutes from the long hand, then the hour from the short hand.

1. Read the minute hand, the long hand. Each number on the clock face is 5 minutes.
   10 fives = 50 minutes
2. Count the small marks past that number. Each small mark is 1 minute.
   50 + 1 = 51 minutes
3. Read the hour hand, the short hand. It shows the hour that has passed, so read the hour before it.
   the hour is 2
4. Write the time. Write the hour, then a colon, then two digits for the minutes.
   2:51

Check. Check: the hour is 2, and the long hand shows 51 minutes.

Watch out. The short hand must be near the hour, and the long hand counts the minutes. Use two digits for minutes, like 7:05.

Method. Add the length of the activity to the start time. Carry extra minutes into the hours.

1. Write the start time. It is where we begin.
   15:43
2. Add the duration. Add 2 hours to the start time.
   15:43 + 2 hours = 17:43
3. Write the finish time. Use two digits for the hour and minutes.
   17:43

Check. Check: 2 hours before 17:43 is 15:43.

Watch out. When the minutes go past 60, add one hour and take away 60 minutes.

Method. Count on from the start time to the end time, in steps: minutes to the next hour, whole hours, then minutes.

1. Count the minutes to the next hour, 07:00. Count on to the next full hour.
   06:02 to 07:00 is 58 minutes
2. Count the whole hours up to 07:00. Each full hour is 60 minutes.
   0 hours = 0 minutes
3. Count the minutes from 07:00 to 07:06. Count on the last minutes.
   6 minutes
4. Add the parts. Add the minutes from each part.
   58 + 0 + 6 = 64
5. Write the duration. Give the answer in hours and minutes.
   1 hour 4 minutes

Check. Check: 06:02 plus 1 hour 4 minutes is 07:06.

Watch out. Count the minutes to the next hour first. Do not subtract the hours and the minutes separately.

Method. Use the facts: 60 minutes in an hour, 24 hours in a day, and the number of days in each month.

1. Remember how many hours there are in 1 day. There are 24 hours in 1 day.
   1 day = 24 hours
2. Multiply by 1. There are 1 days.
   1 × 24 = 24
3. Write the answer. This is the total number of hours.
   24

Check. Check the fact: 60 minutes, 24 hours, or the days in the month.

Watch out. Learn the months with 30 days: April, June, September and November. All the others have 31 days, except February.

Method. A 24-hour clock counts from 00:00 to 23:59. Add 12 to the hour for p.m. times.

1. Note the time of day. a.m. is the morning. p.m. is after 12 noon.
   a.m.
2. Change the hour. For p.m. times, add 12 to the hour, unless it is 12. For a.m. times, keep the hour, and 12 a.m. is 00.
   9 stays the same
3. Write the time. Keep two digits for the hour and minutes.
   09:02

Check. Check: 09:02 is 9:02 a.m..

Watch out. 12:30 p.m. is 12:30 on a 24-hour clock, not 00:30. Midnight is 00:00.

Method. Count on from the start time to the end time, in steps: minutes to the next hour, whole hours, then minutes.

1. Count the minutes to the next hour, 08:00. Count on to the next full hour.
   07:14 to 08:00 is 46 minutes
2. Count the whole hours up to 07:00. Each full hour is 60 minutes.
   -1 hours = -60 minutes
3. Count the minutes from 07:00 to 07:49. Count on the last minutes.
   49 minutes
4. Add the parts. Add the minutes from each part.
   46 + -60 + 49 = 35
5. Write the duration. Give the answer in hours and minutes.
   35 minutes

Check. Check: 07:14 plus 35 minutes is 07:49.

Watch out. Count the minutes to the next hour first. Do not subtract the hours and the minutes separately.

Method. There are 60 minutes in an hour. Multiply hours by 60 to change to minutes, or divide minutes by 60 to change to hours.

1. Change 1 hour to minutes. There are 60 minutes in 1 hour.
   1 × 60 = 60
2. Add the minutes. Put the extra minutes on the end.
   60 + 18 = 78
3. Write the answer. This is the total number of minutes.
   78

Check. Check: 1 hour is 60 minutes, and 18 more is 78.

Watch out. Do not write 2 hours 135 minutes. Change every 60 minutes into 1 hour.

Method. Convert between the 12-hour and 24-hour clock. The minutes stay the same.

1. Find the hour on a 12-hour clock. Subtract 12 from the hour if it is after 12. Midnight and noon are 12.
   09 is 9 on a 12-hour clock
2. Decide a.m. or p.m. Times before 12:00 are a.m. and times from 12:00 are p.m.
   a.m.
3. Write the time. Write the hour, the minutes, then a.m. or p.m.
   9:24 a.m.

Check. Check: 9:24 a.m. is the same time of day as 9:24 a.m..

Watch out. The minutes never change. Only the hour changes on the 24-hour clock.

Method. There are 60 minutes in an hour. Multiply hours by 60 to change to minutes, or divide minutes by 60 to change to hours.

1. Change 3 hours to minutes. There are 60 minutes in 1 hour.
   3 × 60 = 180
2. Add the minutes. Put the extra minutes on the end.
   180 + 39 = 219
3. Write the answer. This is the total number of minutes.
   219

Check. Check: 3 hours is 180 minutes, and 39 more is 219.

Watch out. Do not write 2 hours 135 minutes. Change every 60 minutes into 1 hour.

Method. Use the facts: 60 minutes in an hour, 24 hours in a day, and the number of days in each month.

1. Remember how many minutes there are in 1 hour. There are 60 minutes in 1 hour.
   1 hour = 60 minutes
2. Multiply by 10. There are 10 hours.
   10 × 60 = 600
3. Write the answer. This is the total number of minutes.
   600

Check. Check the fact: 60 minutes, 24 hours, or the days in the month.

Watch out. Learn the months with 30 days: April, June, September and November. All the others have 31 days, except February.

Method. Read the minutes from the long hand, then the hour from the short hand.

1. Read the minute hand, the long hand. Each number on the clock face is 5 minutes.
   0 fives = 0 minutes
2. Count the small marks past that number. Each small mark is 1 minute.
   0 + 3 = 3 minutes
3. Read the hour hand, the short hand. It shows the hour that has passed, so read the hour before it.
   the hour is 1
4. Write the time. Write the hour, then a colon, then two digits for the minutes.
   1:03

Check. Check: the hour is 1, and the long hand shows 3 minutes.

Watch out. The short hand must be near the hour, and the long hand counts the minutes. Use two digits for minutes, like 7:05.