Decimal grid or area models can be used to understand the process of addition and subtraction using decimal numbers.
The below the grids models are represents the decimal numbers \(1.0\), \(0.1\) and \(0.01\).
Now let us do the addition using these grids.
Find the sum of \(0.22\) and \(0.67\).
Here, \(0.22\) can be written as , similarly \(0.67\) can be written as .
In the grid model first shade the region of \(0.22\) followed by \(0.67\). Here we denote the decimal in different to understand it clearly.
Therefore, the total shaded region is the sum of \(0.22\) and \(0.67\). That is \(0.22 + 0.67 = 0.89\).