Netherlands
2. Arithematic
2.1. Numbers
2.1.1. Successor and Predecessor
2.1.2. Odd and Even Numbers
2.1.3. Prime and Composite Numbers
2.1.3.2. Composite Numbers
2.1.3.3. Prime Numbers
2.1.3.5. Twin Primes
2.1.3.6. Prime Triplet
2.1.3.7. Co-Primes
2.3. Fractions
2.5. Decimals
2.6. Unitary Method
2.7. Rounding Numbers
2.8. Percentage
2.9. Profit and Loss
2.10. Simple Interest
2.12. Mensuration
2.13. Time
2.14. Data Interpretation