Length: Comparing, adding and subtracting

​​In a nutshell

Length is how you describe how long an object is compared to another. You can compare the sizes of objects using length and for small enough objects you can use a ruler to measure this.

Comparing length

Bigger objects have bigger lengths, so a $$20cm$$​ fork is bigger than a $$5cm$$​ eraser. Remember that you can only compare lengths if they have the same unit; an $$11cm$$ pencil is not longer than a $$2m$$​ table! Use this equation to convert between units:

​$$100cm = 1m = 0.001km$$

Adding and subtracting length

procedure

Example

How much longer is a $$1.2m$$​ table compared to a $$65cm$$​ chair?

​$$1.2m = 120cm$$

$$120 - 65 = \underline{55cm}$$

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