If a recipe calls for whole milk and you only have dry milk, what would you do? Explain your answer. 
I was able to find this pretty easily online:  1 Cup Milk = 1 Cup Water + 3 Tablespoons Powdered Milk 3/4 Cup Milk = 3/4 Cup Water + 2 1/4 Tablespoons Powdered Milk 2/3 Cup Milk = 2/3 Cup Water + 2 Tablespoons Powdered Milk 1/2 Cup Milk = 1/2 Cup Water + 1 1/2 Tablespoons Powdered Milk 1/3 Cup Milk = 1/3 Cup Water + 1 Tablespoon Powdered Milk 1/4 Cup Milk = 1/4 Cup Water + 3/4 Tablespoon Powdered Milk   Source: http://preparednessadvice.com/food_storage/conversion-chart-for-powdered-milk/   Additionally, I've done some calculations to show why this works for creating 1 cup milk (a little bit more :)  Dry milk composition in %                  Protein (%)  Fat (%)    Sugar (%)   Minerals (%) Water (%) Dry milk, Fullfat   26       27      38          6               2.5 Dry milk, nonfat    36       1       52          8                3 Fresh milk         3.4      3.7     4.8          1               87   Dry milk composition in 42 ml (3 tbsp)..just converting % to ml                                     Protein(ml)   Fat(ml) Sugar(ml)   Minerals(ml) Water(ml)  Dry milk, Fullfat   10.9        11.3        16.0      2.5            1.1 Dry milk, nonfat    15.1        0.4         21.8      3.4            1.3 Fresh milk          3.4         3.7         4.8       1.0            87.0   If you add 1 cup water = 42+236 ml liquid  Dry milk with water                    Protein (%)    Fat (%) Sugar (%)   Minerals (%)    Water (%) Dry milk, Fullfat   3.9          4.1      5.7         0.9            85.3 Dry milk, nonfat    5.4          0.2      7.9         1.2            85.4 Fresh milk          3.4         3.7      4.8          1              87   Which is nearly the same as whole fresh milk.  Source for dry milk stats (1st table): On Food and Cooking by Harold McGee. 