Number Play

Choose two integers; they need not be different.  Add them together. Record the units digit of the sum and append that to the sequence.  Obtain the next number by repeating the operation on the second and third number you just calculated.

• Eg 56, 3
• 56 + 3 = 59
• units digit = 9
• 3 + 9 = 12, units digit = 2
• etc

Write the units digits in a list box.  Repeat the process 50 times.

Investigate if anything interesting happens to the sequence.

Also try:

1. triples,
   
2. subtracting,
   
3. randomly adding or subtracting depending on a toss of a coin.