Arithmetics

Makefile

leading_zero_strip = $(shell echo $$(echo $(1) | sed 's/^0*//'))

__plus = $(shell echo $$(($(1) + $(2))))
plus = $(call __plus,$(call leading_zero_strip,$(1)),$(call leading_zero_strip,$(2)))

__minus = $(shell echo $$(($(1) - $(2))))
minus = $(call __minus,$(call leading_zero_strip,$(1)),$(call leading_zero_strip,$(2)))

__mult = $(shell echo $$(($(1) * $(2))))
mult = $(call __mult,$(call leading_zero_strip,$(1)),$(call leading_zero_strip,$(2)))

__div = $(shell echo $$(($(1) / $(2))))
div = $(call __div,$(call leading_zero_strip,$(1)),$(call leading_zero_strip,$(2)))


A = 5 
B = 10
C = 45

.DEFAULT: all

all:
	@echo $(call plus,$(A),$(B))
	@echo $(call minus,$(C),$(A))
	@echo $(call mult,$(A),$(B))
	@echo $(call div,$(C),$(A))