When we add decimals together, we need to "line up the decimal point" to make sure that we are adding the equivalent values together. Let's start by looking at a place value table.
Notice that the decimal point is to the right of the ones or units column. After the decimal point comes the tenths column, then the hundredths column. These columns are parts of a whole.
Similar to when we add whole numbers, when we add decimals, we start from right to left and "spill over" any extra values. Let's watch a video to see this process in action.
Start by adding the values in the smallest place value column up work up.
i.e. Work from right to left.
Find $0.02+0.04$0.02+0.04 giving your answer as a decimal.
Find $0.12+0.33$0.12+0.33 giving your answer as a decimal.