To calculate the sine of $30^\circ$ using a scientific calculator, follow these steps:

1. Set the Calculator to Degree Mode: Before you begin, make sure your calculator is configured to degree mode, as many calculators can also operate in radians. You can typically switch between modes by pressing a button labeled “DRG” or “MODE” until “DEG” is displayed on the screen.

2. Access the Sine Function: Once your calculator is in degree mode, locate the “sin” button. This button is usually found on the main interface of the calculator. If it is a secondary function, you may need to press a “shift” or “2nd” button first.

3. Input the Angle: After pressing the “sin” button, enter the angle $30$. To do this, press the following keys in sequence: first “sin,” then “3,” followed by “0.”

4. Calculate the Result: Finally, press the equals button, which is typically marked as ”=” or “EXE.” Your calculator will then display the result, which is $0.5$. This indicates that the sine of $30^\circ$ is $0.5$.

Understanding how to perform this calculation is crucial for solving trigonometry problems in your GCSE Maths exams. The sine function is one of the key trigonometric functions, linking the angles of a triangle to the lengths of its sides. Mastering the use of your calculator can save you time and help you verify your answers efficiently.