Put numbers into a formula and work it out in the right order, with negatives, squares and roots.
What you will learn
- Substitute into formulae from maths and science
- Handle negative values and powers
- Use a calculator for roots and π
Replace, then follow the order
A formula connects quantities: v = u + at gives the speed v after time t.
Replace each letter with its value, in brackets, then use the order of operations.
- v = u + at, u = 4, a = 2.5, t = 6
- v = 4 + 2.5 × 6
- = 4 + 15 = 19
Multiplication happens before addition, so 4 + 2.5 × 6 is not 6.5 × 6.
The rest of this lesson and its 7 practice questions are locked.
In this lesson
- Replace, then follow the order
- Squares, halves and roots
- Try it: Formulae on the calculator
7 practice questions, marked as you go; about 20 minutes in all.
In this unit: Formulae and rearranging
Substitute into formulae, write your own, change the subject (including when it appears twice) and use rearranged formulae from science and finance.
- Substituting into formulae
- Writing formulae
- Changing the subject
- When the subject appears twice
- Using formulae