Measuring Problem

First thought: grams is a measure of weight, ounces is a measure of volume, well OK, weight in some cases.

An ounce of volume equals an ounce of weight ONLY for water or anything else with a specific weight of 1

75 grams is equal to 2.6455 ounces of weight, not volume !(28.3495231 grams/1 ounce (weight))

Granulated sugar has a specific weight of, approximately, 0.849, so 2.6455 ounces (weight) will be approximately 3.11 ounces (volume), so I would use 3 ounces (volume) or 6 tablespoons or 18 teaspoons.

Flour is a lot trickier, the specific weight varies with the variety, the fineness, whether it is scooped, sifted, etc. Generally, if it is gently spooned into a measuring cup and then struck off with a straight edge, the specific weight is very close to 0.5625, but it can be as high as 0.75 if it is somewhat packed. So, for 75 grams of flour which equals the same 2.6455 ounces (weight), the approximate volume would be 4.7 ounces (volume) in the first case to 3.53 in the second. I'd figure the first case, 4.7 ounces (volume) and I'd probably round off to 1/2 cup + 1 1/2 tablespoons.

The simple solution? Buy a digital kitchen scale that has a grams/ounces conversion and weight everything

You can use Food Densities (weight/volume relationships) to find the specific weights as well

Here is a converter that might help you convert grams to cups for various types of flour.

Set the left column to GRAMS and the right column to the type of flour and cups

Here's another calculator that might be of more help

Generally it is better to weigh dry ingredients, especially when doing baking and when trying to duplicate someone else's recipe. 75g of sugar will always be 75g of sugar no matter what as long as you are using an accurate scale. Measuring a cup of sugar will not always give you the exact same amount. I know it's a little bit of hyperbole, but consider powdered vs. granulated sugar. 1 cup of one is not the same as the other. 1 cup that one person measures may not be the same as 1 cup of the same sugar that another person measures because of the way the go about measuring.

Your best bet is to get a digital scale that measures in multiple types of units so you know that if that souffle doesn't rise, or that bread is way to dense, that it wasn't because you measured wrong.