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Children are taught formal procedures of multiplication at school. However, they frequently develop their own informal methods which are quicker and easier to do than these formal algorithms. Those with a good understanding of place value and number principles will devise their own methods of multiplication or various methods to suit specific questions. It is important that such alternative and logically correct methods be accepted and encouraged so that children are not 'put off ' mathematics as a whole.

According to Professor Norman Myers, one of the foremost authorities on rates of deforestation in tropical forests, "the annual destruction rate seems set to accelerate yet further, and could well double in another decade" (Myers 1992). As Myers points out, "we still have half of all tropical forests that ever existed". The struggle to save the world's rainforests continues, and there is a growing worldwide concern about the issue. In order to save rainforests, we need to know why they are being destroyed. Nobody knows exactly how much of the world's rainforests have already been destroyed and continue to be razed each year. Data is often imprecise and subject to differing interpretations. However, it is obvious that the area of tropical rainforest is diminishing and the rate of tropical rainforest destruction is escalating worldwide, despite increased environmental activism and awareness. A 1992 study by the Food and Agriculture Organisation (FAO) placed the global rate of tropical deforestation at 17 million ha. per year. A study by the World Resources Institute (WRI) suggests that the figure could be as high as 20.4 million ha. per year. 1. Immediate Causes The immediate causes of rainforest destruction are clear. The main causes of total clearance are agriculture and in drier areas, fuelwood collection. The main cause of forest degradation is logging. Mining, industrial development and large dams also have a serious impact. Tourism is becoming a larger threat to the forests. 1.1 Logging Commercial logging companies cut down mature trees that have been selected for their timber. The timber trade defends itself by saying that this method of 'selective' logging ensures that the forest regrows naturally and in time, is once again ready for their 'safe' logging practices (WWF). In most cases, this is untrue due to the nature of rainforests and of logging practices. Large areas of rainforest are destroyed in order to remove only a few logs. The heavy mac

"A land mine is a target (person or vehicle) triggered explosive weapon . Their non-explosive predecessors (caltrops, stakes and spikes) have been used on the battlefield since ancient times. Landmines were designed to be used to deter, channel, delay and kill an enemy. They have been used in various formats, for centuries and have featured in all major conflicts. Land mines are force multipliers , meaning that they may increase the efficiency of a force without requiring more personnel. The name originates from the practice of mining , where tunnels were dug under enemy fortifications or forces. These tunnels ("mines") were first collapsed to destroy fortifications above, and later filled with explosives and detonated. Land mines generally refer to devices specifically manufactured for this purpose, as distinguished from improvised explosive devices ("IEDs"). The use of land mines is controversial because they are indiscriminate weapons, harming soldier and civilian alike. They remain dangerous after the conflict in which they were deployed has ended, killing and injuring civilians and rendering land impassable and unusable for decades. To make matters worse, many factions have not kept accurate records (or any at all) of the exact locations of their minefields, making removal efforts painstakingly slow. These facts pose serious difficulties in many developing nations where the presence of mines hampers resettlement, agriculture, and tourism. The International Campaign to Ban Landmines campaigned successfully to prohibit their use, culminating in the 1997 Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on their Destruction, known informally as the Ottawa Treaty . As of 2007, a total of 158 nations have agreed to the treaty. Thirty-seven countries have not agreed to the ban, including China , India , Israel , Pakistan

red eyed tree frogs are quite amazing