#### Weight Conversions

S
```# A ruby program for weight conversions

module WeightConversion
# Kilogram -> Gram = (kilogram_value * 1000) grams
def self.kilogram_to_gram(kilogram_input)
raise StandardError unless kilogram_input.is_a?(Integer)

gram = kilogram_input * 1000

"#{kilogram_input} kg = #{gram} g"
end

# Gram -> Kilogram = (gram_value / 1000) kilograms
def self.gram_to_kilogram(gram_input)
kilogram = gram_input / 1000

"#{gram_input} g = #{kilogram} kg"
end

# Pound -> Ounce = (pound_value * 16) oz
def self.pound_to_ounce(pound_input)
ounce = pound_input * 16

"#{pound_input} lb = #{ounce} oz"
end

# Ounce -> Pound = (ounce_value / 16) lb
def self.ounce_to_pound(ounce_input)
pound = ounce_input / 16

"#{ounce_input} oz = #{pound} lb"
end

# Kilogram -> Pound = (kilogram_input * 2.205) lb
def self.kilogram_to_pound(kilogram_input)
pound = (kilogram_input * 2.205).round(2)

"#{kilogram_input} kg = #{pound} lb"
end

# Pound -> Kilogram = (pound_input / 2.205) kg
def self.pound_to_kilogram(pound_input)
raise StandardError unless pound_input.is_a?(Integer)

kilogram = (pound_input / 2.205).round(2)

"#{pound_input} lb = #{kilogram} kg"
end
end

#
# Valid inputs
#

puts WeightConversion.kilogram_to_gram(2)
# 2 kg = 2000 g
puts WeightConversion.gram_to_kilogram(3000)
# 3000 g = 3 kg
puts WeightConversion.pound_to_ounce(16)
# 16 lb = 256 oz
puts WeightConversion.ounce_to_pound(16)
# 16 oz = 1 lb
puts WeightConversion.kilogram_to_pound(1)
# 1 kg = 2.21 lb
puts WeightConversion.pound_to_kilogram(100)
# 100 lb = 45.35 kg

#
# Invalid inputs
#

begin
puts WeightConversion.kilogram_to_gram('a')
rescue StandardError
puts 'Error: Please provide number only!'
end

begin
puts WeightConversion.kilogram_to_gram('3000')
rescue StandardError
puts 'Error: Please provide number only!'
end

begin
puts WeightConversion.kilogram_to_gram('16')
rescue StandardError
puts 'Error: Please provide number only!'
end

begin
puts WeightConversion.kilogram_to_gram('x ')
rescue StandardError
puts 'Error: Please provide number only!'
end

begin
puts WeightConversion.kilogram_to_gram('weight')
rescue StandardError
puts 'Error: Please provide number only!'
end

begin
puts WeightConversion.kilogram_to_gram('100')
rescue StandardError
puts 'Error: Please provide number only!'
end
```