From looking at original German recipes and their translations, "3 Tr" would mean "3 Tropfen" or "3 drops". Drops can vary in size.
It would be pretty difficult to eye the difference between 1/32 and 1/25 of a teaspoon. I'm not so certain your taste buds would pick up the difference in a cookie or cake recipe. I'd probably get a dropper bottle to use for that recipe, but realize that even drops vary in volume.
Approximately 5 grams
You can't buy a teaspoon of vanilla at any store.
Typically, you can use about 1 teaspoon of almond extract for a standard banana bread recipe. This amount enhances the flavor without overpowering the bananas. If you prefer a stronger almond taste, you can increase it to 1.5 teaspoons, but be cautious not to exceed that, as it can become too pronounced.
enough??? daaa!
I'm assuming you mean vanilla extract. Pure Vanilla extract is more expensive but it is of much higher quality You can't buy just one teaspoon.. you can buy small bottles but they're at least 6 teaspoons (one fluid ounce) that'll run you about $4-5
Almond extract is just a flavoring, you can substitute any other flavor for it. This of course changes what you are making. Vanilla would be a common substitute or Rum depending on what the recipe is.
1/4 teaspoon
Depends where you buy it.
I'd say 1/2 teaspoon to 1 teaspoon per batch.
Depends where you buy it.
You can't buy it by the teaspoon. A small bottle is about $2
The oil is much more potent and should be used sparingly. Extracts are made with alcohol and are therefore already diluted. If a recipe calls for 1 teaspoon extract you should only use 1/4 teaspoon of the oil.