Question 18693
Well, you first need to know the conversion rates
1 pound = 0.45359237 kilograms
16 ounces = 1 pound

8 oz = {{{1/2}}}pound
51 lb = 23.13 kg
{{{1/2}}} pound = .23 kg

{{{addition_cartoon(23.13,.23)}}}
You should end up with 23.36kg

Hope this helps!