Notice & predict
Earlier, then later
Draw the three date examples.
Curiosity Bundle
Why does Diwali fall on a different date every year?
Two ways of keeping time do not line up neatly.
Compare real date examples, explore Moon cycles and try an approximate calendar model that has an important limit.
IgniteStart with the puzzle
Say, "The India listing has Diwali on October 31 in 2024, October 20 in 2025 and November 8 in 2026. Why did it move earlier, then later?"
Offer one puzzle. Leave room for a guess.
Say, "The India listing has Diwali on October 31 in 2024, October 20 in 2025 and November 8 in 2026. Why did it move earlier, then later?"
Another way to begin
Show two strips that begin together but end apart. Ask, "What would happen if we repeated both lengths?"
Use these printed date examples. No sky observation or family festival calendar is needed.
KindleEarlier, then later
Notice and predict before reading. Keep your first idea.
ReadExplore the custom and its context
Both readings are part of the exploration. Read together or across days.
DoTry it and compare
Notice what changes and what your model cannot tell you.
Investigation
Repeat the gap, then try an adjustment
Join proportional model bars.
CheckWhat would you say now?
Revisit the readings and activities. Parent answers print separately.
A light check
What would you say now?
Revisit cycle and calendar type.
Sources and review notes
Local review edition. Physical activities, diagrams, and family usability still need review. Times are estimates. See the parent guide for each activity’s safety instructions and model limits.
- Moon PhasesPhase cycle and daytime positioning only; no fixed observation time or sky orientation.
- Diwali in IndiaBrief source; India listing for 2024 2025 2026 only; local observance may differ.
- Calendars from around the worldDisclosed additional museum source; rounded lunar and solar length comparison only; older specific calendar descriptions not adopted.
- Hindu Calendar Indian CalendarDisclosed additional calendar research source; lunisolar information and extra months only; regional rules differ.