Maths tricks · trick 13 of 25 · free

Day-of-the-week puzzles — Maths trick for kids

After every 7 days it is the same day of the week again. So to jump many days ahead, throw away whole weeks and count only the days left over.

The trick

Leftover days — “divide by 7 and count only the leftover days”

  1. Divide the number of days by 7 and keep the remainder.
  2. Count that many days forward from today (backward for “days ago”).
  3. Two dates in the same month: the days between them = later date − earlier date.

Use it for: Planning holidays and birthdays, calendar questions in reasoning tests, and Olympiad puzzles.

Worked example: If today is Tuesday, what day will it be after 30 days? Thursday

  1. 30 = 7 × 4 + 2, so only 2 days matter.
  2. Count 2 days on from Tuesday: Wednesday, Thursday.

Check: After 28 days it is Tuesday again; 2 more days → Thursday ✓

✏️ Practice

Work it out in your head or on paper, type the answer and press Check. Stuck? Press “Show me how”.

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🏁 Trick 13 test

20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.

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🖨️ Day of the Week Puzzles Worksheet

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