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Raksha Bandhan (Smart Rakhi Bead Multiplication Matrix)

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Decorate Rakhis by arranging beads on a 10x10 grid matrix board. Magnetic Hall-effect sensors under the grid detect the row x column array (e.g. 4 rows of 6 beads) and display multiplication tables with sound.

Categorisation

Props & Materials Required

  • 10x10 magnetic pegboard grid
  • Magnetic decorative Rakhi beads (40 items)
  • 100x Hall-effect / reed switch matrix array or row/column touch grid
  • ESP32 controller board
  • 0.96-inch OLED display
  • DFPlayer Mini MP3 module + 3W speaker

Step-by-Step Instructions

1

Set Up Rakhi Array

Place beads to make 4 rows with 6 beads in each row on the grid.

2

Smart Grid Matrix Scan

Grid sensors scan the array: 4 Rows × 6 Columns.

3

Multiplication Table Announcement

OLED displays '4 × 6 = 24'. Speaker narrates: '4 groups of 6 beads equals 24 total beads! 4 times 6 is 24!'

4

Commutative Property Test

Rotate the board 90° to make 6 rows of 4 beads. Grid confirms: '6 × 4 = 24! The total stays the SAME!'

Why It Works & Notes

Multiplication tables are easily memorized when visualized as 2D rectangular arrays (rows × columns). Building a 4x6 Rakhi bead array on a smart grid shows that 4 rows of 6 beads equals 24 total beads.