Presentation on theme: "FRACTIONS. Exercise 1 What fraction of the deposit is left? What fraction of the deposit has been used up? What fraction of the deposit will be left if."— Presentation transcript:
Exercise 1 What fraction of the deposit is left? What fraction of the deposit has been used up? What fraction of the deposit will be left if we use half of the deposit? The fuel tank has a capacity of 12 gallons. How much fuel do we have left? How much have we used up?
Exercise 2 Un coche híbrido (cuyo motor combina el uso de gasolina y electricidad) consume 3 litros de gasolina por cada 100 km recorridos. Sabemos que en el depósito caben 48 litros. ¿Cuántos km podemos recorrer con la gasolina disponible? ¿En qué posición estará la aguja tras recorrer 400 km?
Exercise 4 What fraction of the Earth is covered by the oceans? What fraction of the Earth is covered by land? The Atlantic Ocean has a total area of about 108 million km 2. What fraction of the Earth is that? What fraction of the oceans? The total area of the Earth is approximately 510 millon km 2 and the oceans cover about 360 million square kilometers.
Exercise 5 The population of Europe is estimated to be approximately 700 million. There are 6300 million people in the world. What fraction of the people of the world are Europeans? According to Wikipedia, “a century ago, Europe had nearly a quarter of the world’s population”. In 1900, the population of Europe was 325 million. Has the population of Europe increased or decreased? What about the fraction of the European people in the world?
Exercise 6 There are about 1400 millions km 3 of water on the planet Earth. of all that water is in the oceans, and the rest is fresh water. What fraction of the Earth water is fresh? How many km 3 of fresh water are there?
Exercise 7 The xilophone is a percussion instrument. It consists of wooden bars of various lengths that are struck by mallets. Each bar is tuned to a specific note of the musical scale. In the picture, bars with the same color produce the same note, only one octave above. Look at the red bars. The smaller one is exactly half as long as the bigger one. How long are the rest of them?