100 calorie snack ideas?

Well that can vary a lot!

You can do a cheese stick, a handful of nuts, a whole ton of bell peppers, carrot sticks, a small tub of yogurt, cucumber slices with a little hummus, a medium apple, an orange, a banana, a small oatmeal cookie, a slice of toast, a spoonful of peanut butter (on celery, even!), a whole salad of just veggies and a very light dressing, some pretzels, tortilla chips and salsa/guacamole (check serving sizes on the chips)...