9.11+Percentages

I can:


 * Convert between fractions and percentages
 * Convert between decimals and percentages
 * Express one quantity as a percentage of another e.g. 15 out of 20 = 75%
 * Find a percentage of a quantity e.g. 60% of 50 = 30
 * Increase a quantity by a %
 * Decrease a quantity by a %