Potassium Content of Tomatoes. The size of the tomato you eat influences how much potassium you'll get from the vegetable. One large tomato contains 431 milligrams of potassium, which is almost 10 percent of your daily requirement. One medium-sized tomato supplies 292 milligrams of potassium and a small tomato provides 216 milligrams. A plum tomato or an Italian tomato each contains 147 milligrams of potassium.
The abacus, called Suan-Pan in Chinese, as it appears today, was first chronicled circa 1200 C.E. in China. The device was made of wood with metal re-inforcements. On each rod, the classic Chinese abacus has 2 beads on the upper deck and 5 on the lower deck; such an abacus is also referred to as a 2/5 abacus.
Report Abuse. The origins of the abacus are disputed; many cultures are known to have used similar tools. It is known to have first existed in Mesopotamia[1][2] and China,[3] and was invented sometime between 1000 BC and 500 BC.[4] The first abacus was almost certainly based on a flat stone covered with sand or dust.