Question: Explain how to add these weights: $14$ ounces, $1$ pound $2$ ounces, and $1$ pound $6$ ounces.

Sample answer: Add the ounces together and the pounds together separately. Here, $14 + 2 + 6 = 22$ ounces and $0 + 1 + 1 = 2$ pounds, giving $2$ pounds $22$ ounces. Since $1$ pound $= 16$ ounces, convert: $22 \div 16 = 1$ remainder $6$, so $22$ ounces $= 1$ pound $6$ ounces. Add that pound to the $2$ pounds for a total of $3$ pounds $6$ ounces.

Key points:

• Add all ounce values together first
• Add all pound values together separately
• Know that $1$ pound $= 16$ ounces
• Divide the ounce total by $16$ to find extra pounds and leftover ounces
• Add the extra pounds to the pound total for the final answer

Rubric: Full credit for adding ounces and pounds separately, correctly converting the excess ounces to pounds using $16$ ounces $= 1$ pound, and stating the correct final total. Partial credit if the units are added correctly but the conversion step is missing or incorrect.