1.1 Real Numbers

• Classifying real numbers: natural, whole, integers, rational and irrational
• Operations on real numbers
• Order of operations
• Rounding, significant figures and approximation
• Standard form

• classify numbers as rational or irrational
• perform operations on real numbers in the correct order
• round numbers to a given number of decimal places or significant figures
• express numbers in standard form
• appreciate the use of real numbers in real life situations

“How are numbers used to describe quantities in real life?”

The titles are open to everyone. Reading a lesson needs an account — sign in or create one.

1. Classifying real numbers
   40 min · 2 practice tasks · quiz
   What the number sets are, how they nest, and the one test that separates them.
2. Accuracy and standard form
   40 min · 2 practice tasks · quiz
   Order of operations, rounding sensibly, and writing very large or small numbers.
3. Odd, even, prime and composite
   40 min · 1 practice tasks · quiz
   How whole numbers split into odd and even, and into prime and composite.
4. The real number line
   40 min · 1 practice tasks · quiz
   Every real number is a point on a line, and left means smaller.
5. Adding and subtracting real numbers
   40 min · 1 practice tasks · quiz
   Directed jumps on the number line, and subtracting as adding the opposite.
6. Multiplying and dividing real numbers
   40 min · 1 practice tasks · quiz
   The sign rules for products and quotients, and why negative times negative is positive.
7. Reciprocals by division
   40 min · 1 practice tasks · quiz
   The reciprocal of a number is 1 divided by that number, and a number times its reciprocal is 1.
8. Reciprocal tables, calculators and real life
   40 min · 1 practice tasks · quiz
   Reading a reciprocal from tables or a calculator, and using it in a computation.