Pigeonhole Puzzles part 3

Two more Pigeonhole Puzzles are solved. A more efficient method for finding the missing digit in the difference is shown and explained.
View part 1 here...

View part 2 here...

PREVIOUS LESSONS:
Universal Cycle: Bead Necklace part 2...

Finite Fields in Middle School Algebra, part 1...

Is The Pythagorean Theorem Obvious?

The Monkey and the Coconuts...

Universal Cycle: Bead Necklace part 1...

Pie, So-So, & Goose...

Calendar Calculations...

The Harmonic Mean part 3...

Quadratic Functions Mod 7...

Game of Nim...

Pigeonhole Puzzles part 2...

Pigeonhole Puzzles part 1...

Teach Adding and Subtracting...

Bowling Pin Puzzles part 1...

The Harmonic Mean part 2...

The Harmonic Mean part 1...

Completing The Square Backwards...

The Quadratic Formula and a Formula for All Pythagorean Triangles...

Mathematics for Social Justice by Marc Roth.