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\ 10-Nov-2025 Bharat Arora Proof-8 Reader’s Sign _______________________ Date __________

HOTS
21 st
Century #Computational Thinking
Skills
The time taken by each team in two rounds of a swimming championship is given
below. Rank the teams from the fastest (1st) to the slowest (4th) based on the total time

taken in both rounds.

Team A b C d

Round-1 1 h 45 min 10 s 1 h 55 min 19 s 2 h 39 min 10 s 1 h 49 min 36 s

Round-2 2 h 14 min 53 s 2 h 15 min 10 s 2 h 55 min 19 s 2 h 10 min 26 s
Total Time

Rank

Fun Activity

Study the calendar and see the magic of operations. 21 st
Century #Experiential Learning
• Choose any month from a calendar. Skills
march
S M T W T F S

1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31

• Choose any 3 × 3 grid (9 dates) in that month and draw a box around it.
• Find the total of all the numbers in the box by using this short cut.

• Add 8 to the smallest number in the box (i.e. 1 + 8 = 9 in the example).
• Multiply the answer by 9 ( 9 × 9 = 81). The total of all the numbers in the box
= 81.
• Check your answer by actually adding all the numbers in the box.
1 + 2 + 3 + 8 + 9 + 10 + 15 + 16 + 17 = 81

• Do the same with a few more boxes.

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Time