Base 4 Numbers
Allison Lindhorstにより
1. Most Difficult
1.1. Base 4 pieces
1.2. Subtraction
1.3. Multiplication
1.4. Division
1.4.1. Remainders
2. Closed?
2.1. Addition
2.1.1. Yes?
2.1.2. No?
2.2. Subtraction
2.2.1. Yes?
2.2.2. No?
2.3. Multiplication
2.3.1. Yes?
2.3.2. No?
2.4. Division
2.4.1. Yes?
2.4.2. No?