Worked example · IT · Year 7
DCF: Citizenship → Health and well-being
A secure Year 7 response, annotated so you can see which success criterion each part meets. It is also the answer key. Key figures: week 1,540 minutes (25 hours 40 minutes); mean 220 minutes (3 hours 40 minutes) a day; last week 1,400 minutes (23 hours 20 minutes); school nights under 9 hours: Tuesday 8 h 30, Thursday 8 h 5, Sunday 8 h 55; latest light out 21:30, screens off 20:30.
| Day | Session 1 (min) | Session 2 (min) | Total (min) | Total (h and min) |
|---|---|---|---|---|
| Monday | 45 | 110 | 155 | 2 h 35 min |
| Tuesday | 45 | 135 | 180 | 3 h 0 min |
| Wednesday | 30 | 90 | 120 | 2 h 0 min |
| Thursday | 75 | 145 | 220 | 3 h 40 min |
| Friday | 130 | 155 | 285 | 4 h 45 min |
| Saturday | 150 | 260 | 410 | 6 h 50 min |
| Sunday | 70 | 100 | 170 | 2 h 50 min |
Working for Thursday session 2: 20:30 to 21:00 is 30 min, 21:00 to 22:00 is 60 min, 22:00 to 22:55 is 55 min. 30 + 60 + 55 = 145 min.
Every interval found by counting on, with one line of working shown, and each total converted correctly (220 min is 3 h 40, not 2 h 20). Evidences criteria 1 and 2.
(a) 155 + 180 + 120 + 220 + 285 + 410 + 170 = 1,540 minutes. 1,540 ÷ 60 = 25 remainder 40, so 25 hours 40 minutes.
(b) 1,540 ÷ 7 = 220 minutes = 3 hours 40 minutes a day.
(c) 2 hours 20 minutes = 140 minutes. 1,540 − 140 = 1,400 minutes = 23 hours 20 minutes.
Uses remainders to convert minutes to hours, and converts the phone’s figure into minutes before subtracting. Evidences criterion 2.
| Night | Sleep | School night? | Screen off to light out |
|---|---|---|---|
| Monday | 21:45 to 07:00 = 9 h 15 min | Yes | 15 min |
| Tuesday | 22:30 to 07:00 = 8 h 30 min | Yes | 10 min |
| Wednesday | 21:15 to 07:00 = 9 h 45 min | Yes | 60 min |
| Thursday | 23:00 to 07:05 = 8 h 5 min | Yes | 5 min |
| Friday | 23:40 to 09:30 = 9 h 50 min | No | 5 min |
| Saturday | 23:30 to 10:00 = 10 h 30 min | No | 10 min |
| Sunday | 22:05 to 07:00 = 8 h 55 min | Yes | 10 min |
Working for Thursday: 23:00 to 00:00 is 1 h, 00:00 to 07:00 is 7 h, 07:00 to 07:05 is 5 min. 8 h 5 min.
Counts through midnight correctly every time. Evidences criterion 1.
(a) Tuesday (8 h 30, so 30 minutes short), Thursday (8 h 5, so 55 minutes short) and Sunday (8 h 55, so 5 minutes short).
(b) Her two shortest school nights, Thursday and Tuesday, were the nights her screens went off latest (22:55 and 22:20), and she turned her light out only 5 or 10 minutes later. On Wednesday her screens went off at 20:15, a full hour before light out, and she got her longest school-night sleep, 9 h 45. Wednesday is the only school night she followed the advice. Late screens are pushing her bedtime later, and she still has to get up at 07:00.
Uses the numbers to support the pattern instead of just saying “phones are bad”. Evidences criteria 3 and 4.
(a) 07:00 back 9 h 30 min is 21:30. One hour before that is 20:30, so screens off at 20:30.
(b) Thursday total is 220 min. Session 1 stays 16:10 to 17:25 (75 min). 220 − 75 = 145 min for session 2, ending at 20:30, so it starts 145 min earlier: 18:05 to 20:30. Check: 18:05 to 19:00 is 55, to 20:00 is 60, to 20:30 is 30, and 55 + 60 + 30 = 145.
(c)
The plan keeps her screen time but moves it earlier, checks the new times by counting on, and the habits are specific to what happened in her log. Evidences criteria 1 and 5.
Saturday: 410 out of 24 × 60 = 1,440 minutes. 410/1,440 = 41/144, which is a little more than a quarter of the day.
Right: she does sleep longer at the weekend (9 h 50 and 10 h 30). Wrong: lying in until 10:00 makes it harder to fall asleep early on Sunday, so Sunday night was short again, and the tiredness in lessons happens on weekdays.