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Intermittent Fasting worksheet

Grades 3–4 · CCSS 4.MD.A.2, 3.MD.A.1

Solve each problem and show your work. Round answers to 2 decimal places where needed.

1.
Problem 1.
- Fasting schedule: 20:4 (20 h fast, 4 h eating window)
- Last meal finishes at: 15:02
Find: Fast ends at
Answer
2.
Problem 2.
- Fasting schedule: 18:6 (18 h fast, 6 h eating window)
- Last meal finishes at: 00:49
Find: Fast ends at
Answer
3.
Problem 3.
- Fasting schedule: Custom fast length
- Fast length: 16 hours
- Last meal finishes at: 00:57
Find: Fast ends at
Answer
4.
Problem 4.
- Fasting schedule: 18:6 (18 h fast, 6 h eating window)
- Last meal finishes at: 19:53
Find: Fast ends at
Answer
5.
Problem 5.
- Fasting schedule: 12:12 (12 h fast, 12 h eating window)
- Last meal finishes at: 19:02
Find: Fast ends at
Answer
6.
Problem 6.
- Fasting schedule: 14:10 (14 h fast, 10 h eating window)
- Last meal finishes at: 16:33
Find: Fast ends at
Answer
7.
Problem 7.
- Fasting schedule: 18:6 (18 h fast, 6 h eating window)
- Last meal finishes at: 15:40
Find: Fast ends at
Answer
8.
Problem 8.
- Fasting schedule: 16:8 (16 h fast, 8 h eating window)
- Last meal finishes at: 22:40
Find: Fast ends at
Answer
9.
Problem 9.
- Fasting schedule: 16:8 (16 h fast, 8 h eating window)
- Last meal finishes at: 16:55
Find: Fast ends at
Answer
10.
Problem 10.
- Fasting schedule: 12:12 (12 h fast, 12 h eating window)
- Last meal finishes at: 19:16
Find: Fast ends at
Answer

Answer key: Intermittent Fasting worksheet

1. Fast ends at: 11:02 AM (next day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 20 h$ $= 4 h$
2. Find when your fast ends: start at your last meal (3:02 PM) and count forward the hours you fast
  $3:02 PM + 20 h$ $= 11:02 AM (next day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $11:02 AM + 4 h$ $= 3:02 PM$
4. So your eating window each day is
  $11:02 AM – 3:02 PM$
2. Fast ends at: 6:49 PM (same day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 18 h$ $= 6 h$
2. Find when your fast ends: start at your last meal (12:49 AM) and count forward the hours you fast
  $12:49 AM + 18 h$ $= 6:49 PM (same day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $6:49 PM + 6 h$ $= 12:49 AM$
4. So your eating window each day is
  $6:49 PM – 12:49 AM$
3. Fast ends at: 4:57 PM (same day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 16 h$ $= 8 h$
2. Find when your fast ends: start at your last meal (12:57 AM) and count forward the hours you fast
  $12:57 AM + 16 h$ $= 4:57 PM (same day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $4:57 PM + 8 h$ $= 12:57 AM$
4. So your eating window each day is
  $4:57 PM – 12:57 AM$
4. Fast ends at: 1:53 PM (next day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 18 h$ $= 6 h$
2. Find when your fast ends: start at your last meal (7:53 PM) and count forward the hours you fast
  $7:53 PM + 18 h$ $= 1:53 PM (next day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $1:53 PM + 6 h$ $= 7:53 PM$
4. So your eating window each day is
  $1:53 PM – 7:53 PM$
5. Fast ends at: 7:02 AM (next day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 12 h$ $= 12 h$
2. Find when your fast ends: start at your last meal (7:02 PM) and count forward the hours you fast
  $7:02 PM + 12 h$ $= 7:02 AM (next day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $7:02 AM + 12 h$ $= 7:02 PM$
4. So your eating window each day is
  $7:02 AM – 7:02 PM$
6. Fast ends at: 6:33 AM (next day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 14 h$ $= 10 h$
2. Find when your fast ends: start at your last meal (4:33 PM) and count forward the hours you fast
  $4:33 PM + 14 h$ $= 6:33 AM (next day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $6:33 AM + 10 h$ $= 4:33 PM$
4. So your eating window each day is
  $6:33 AM – 4:33 PM$
7. Fast ends at: 9:40 AM (next day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 18 h$ $= 6 h$
2. Find when your fast ends: start at your last meal (3:40 PM) and count forward the hours you fast
  $3:40 PM + 18 h$ $= 9:40 AM (next day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $9:40 AM + 6 h$ $= 3:40 PM$
4. So your eating window each day is
  $9:40 AM – 3:40 PM$
8. Fast ends at: 2:40 PM (next day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 16 h$ $= 8 h$
2. Find when your fast ends: start at your last meal (10:40 PM) and count forward the hours you fast
  $10:40 PM + 16 h$ $= 2:40 PM (next day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $2:40 PM + 8 h$ $= 10:40 PM$
4. So your eating window each day is
  $2:40 PM – 10:40 PM$
9. Fast ends at: 8:55 AM (next day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 16 h$ $= 8 h$
2. Find when your fast ends: start at your last meal (4:55 PM) and count forward the hours you fast
  $4:55 PM + 16 h$ $= 8:55 AM (next day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $8:55 AM + 8 h$ $= 4:55 PM$
4. So your eating window each day is
  $8:55 AM – 4:55 PM$
10. Fast ends at: 7:16 AM (next day)
1. Find your eating window. Each day has 24 hours, so take away the hours you fast
  $24 h - 12 h$ $= 12 h$
2. Find when your fast ends: start at your last meal (7:16 PM) and count forward the hours you fast
  $7:16 PM + 12 h$ $= 7:16 AM (next day)$
3. Find when your eating window closes: count forward the eating hours. Your next fast starts then, 24 hours after the last one began
  $7:16 AM + 12 h$ $= 7:16 PM$
4. So your eating window each day is
  $7:16 AM – 7:16 PM$