require "bignum"
local fmt = require "fmt"

local hamburgers      = bigdec.of("4000000000000000")
local milkshakes      = bigdec.of(2)
local price1          = bigdec.of(5.5)
local price2          = bigdec.of(2.86)
local tax_pc          = bigdec.of(0.0765)
local total_pre_tax   = hamburgers * price1 + milkshakes * price2
local total_tax       = tax_pc * total_pre_tax
local total_after_tax = total_pre_tax + total_tax

fmt.print("Total price before tax : %20s", total_pre_tax:tostring(2))
fmt.print("Tax                    : %20s", total_tax:tostring(2))
fmt.print("Total price after tax  : %20s", total_after_tax:tostring(2))