Surds

Things to remember

• Indices are a useful way of more simply expressing large numbers. They also present us with many useful properties for manipulating them using what are called the Law of Indices.
• Surds are special types of irrational number under radical sign like √5, √21, √33 etc.
• The numbers 1,2,3,4,5..... which are used for counting are called natural numbers or counting numbers. 
• Natural numbers have closed the operations of addition and multiplication.