Identify properties

In this section, you´ll learn how to identify the properties of multiplication and addition and how you can use identification to help solve mathematical problems.

To solve rather hard problems without using a calculator you have to identify all expressions that have the same operation.


$$\begin{array}{lcl} 58+69+91=? \end{array}$$

In this example, you can add in any order you prefer. The sum of the expression will not change if you prefer to add the numbers in a different order.

$$\begin{array}{lcl} 91+58+69=218\\ 58+69+91=218 \end{array}$$

The same is true for multiplication:

$$\begin{array}{lcl} 5\cdot 4\cdot 30=600\\ 4\cdot 30\cdot 5=600 \end{array}$$

Video lesson

Show that the following equation holds true

$$3\cdot a\cdot 4=a\cdot 4\cdot 3$$