Hello Maria, I would be glad to help you with this. Because grams measure weight and cups or tablespoons measure volume, the exact conversion for 100 grams depends entirely on the density of the ingredient you are using. A cup of flour, for example, is much lighter than a cup of sugar.
Here are the standard conversions for 100 grams of the most common baking ingredients using standard US measuring cups and level tablespoons:
All-purpose flour: 100 grams is approximately 3/4 cup plus 1 tablespoon (or about 13 level tablespoons). Be sure to spoon the flour into the measuring cup and sweep the top flat with a knife rather than packing it down.
Granulated white sugar: 100 grams is equal to 1/2 cup (or exactly 8 level tablespoons).
Brown sugar (light or dark, firmly packed): 100 grams is slightly under 1/2 cup, which comes out to about 7 level tablespoons.
Butter: 100 grams equals 7 tablespoons, or a little less than half a cup (around 7/8 of a standard 1-stick butter block).
Liquids (water, milk): 100 grams equals 100 milliliters, which is just under 7 tablespoons, or roughly 1/3 cup plus 1.5 tablespoons.
Powdered (confectioners) sugar: 100 grams is roughly 3/4 cup plus 2 tablespoons.
Rolled oats: 100 grams is about 1 cup plus 2 tablespoons.
I hope this helps your dish turn out wonderfully for your family. If there is a specific ingredient in your recipe that is not listed here, please feel free to ask!