Clinical signs are usually seen 3-5 days after exposure. Second-generation coumarins and indandiones are toxic with a single dose. Second-generation coumarins are a greater hazard than first-generation coumarins if the dog or cat eats a poisoned rat or mouse.
Quick Answer. Fractions were created by the ancient Egyptians in 1800 B.C. Egyptians created a number system on a base 10 concept, which is similar to the numerical systems used in the United States and around the world for creating fractions. Originally, Egyptians used pictures as well as numerals to display and differentiate numbers.
First, a fraction is made up of two integersâone on the top, and one on the bottom. The top one is called the numerator, the bottom one is called the denominator, and these two numbers are separated by a line. The line can be horizontal or slantedâthey both mean the same thing and simply serve to separate the numerator from the denominator.