## Unit 12 Section 1 : Substitution into Formulae 1In this section we practise substituting numbers for the letters in a formula: in other words, we replace the letters in formulae with their numerical values. In formulae, when we want to add or subtract letters, we use the normal symbols for add (+) and subtract (–). If we want to multiply, we only write the multiply sign between numbers, not between numbers and letters or between letters and letters. If we want to divide, we write the division as a fraction.
## Example QuestionIfa = 6. b = 3 and c = 7, calculate the value of:
substitute the value of each letter to get an answer:
If
## ExercisesWork out the answers to the questions below and fill in the boxes. Click on the button to find out whether you have answered correctly. If you are right then will appear and you should move on to the next question. If appears then your answer is wrong. Click on to clear your original answer and have another go. If you can't work out the right answer then click on to see the answer.
You have now completed Unit 12 Section 1
Produced by A.J. Reynolds October 2007 |