Get Function Machines Filling In Missing Digit

Finding the Input Sometimes we will be given the output from a function machine and we need to work out the input. To do this, we work backwards through the machine, doing the inverse operation at each stage.

A function, f, is like a machine that receives as input a number, x, from the domain, manipulates it, and outputs the value, y. The function is simply the process that x goes through to become y.

1:48 4:50 Finding the Rule for a Function Machine - YouTube YouTube Start of suggested clip End of suggested clip Seven times five equals 35. I will now test it on the eight eight times five is forty. I think IMoreSeven times five equals 35. I will now test it on the eight eight times five is forty. I think I found my rule. But I want to test some more so at four in times five is 25 times 5 25.

The difference between formulas and function machines is that you must follow a function machine in the correct order from left to right, or top to bottom, as shown in the example below. In the Level 2 course on maths you will see that when you use formulas, the BIDMAS rule must be followed.

In order to solve an equation using a function machine: Consider the order of operations being applied to the unknown. Draw a function machine starting with the unknown as the Input and the value the equation is equal to as the Output. Work backwards, applying inverse operations to find the unknown Input.

The function machine is a way of thinking about three aspects that make up a function: the inputs, the outputs and the rule that determines their connection (Figure 2).

Function machines is part of our series of lessons to support revision on functions in algebra.