Slicing method:
The slicing method is a method of economic analysis used in microeconomics for in-depth study of economic units.
In this method, the economy is divided or 'sliced' into smaller units like individual households, individual firms etc.
Lumping method:
The lumping method is a method of economic analysis used in macroeconomics to study the economy as a whole.
In this method, economic units are lumped together and studied, for example, national income, aggregate demand etc. Thus, individual units are ignored.