 Hello and welcome to the session. In this session we are going to discuss the following question and the question says that, find the value shown by the arrow on the following scale. Now let us start with the solution of the given question. Here we are given a metric ruler where the smaller lines represent millimetres and larger lines with numbers represent centimetres. Before taking the reading, let us find the value of each small division on the scale. This can be easily calculated by dividing the difference between two consecutive numbers on the scale by the number of divisions between them. Now let us take the two numbers 2 and 3. Number of divisions between them is equal to 10. So the value of each small division will be equal to 3 minus 2 whole upon 10 that is equal to 1 by 10 which is equal to 0.1. So the value of each small division is 0.1. Now let us find the value shown by the arrow on the given scale. On the scale you can see this larger line represents 6 centimetres since the value of each small division is 0.1. So this next small line after this will represent 6 plus 0.1 that is equal to 6.1 centimetres. Now here you can see the arrow is representing 1, 2, 3, 4, 5, 6, 7, 8 and 9th line after 6 centimetres. So it is representing 6.9 centimetres. Also we know that 1 centimetre is equal to 10 millimetres or 1 millimetre is equal to 1 by 10 centimetres. So 6.9 centimetres will be equal to 6.9 into 10 millimetres that is equal to 69 millimetres. So the arrow on this scale represents 6.9 centimetres or 69 millimetres or we can find the same using another method that is we are given a metric ruler where the smaller lines represent millimetres and larger lines with numbers represent centimetres. Now in the given scale we have to notice the difference in increment of millimetres and centimetres. Here from 2 centimetres to 3 centimetres you can notice that there are 10 small divisions. So 1 centimetre is equal to 10 millimetres or 1 millimetre is equal to 1 by 10 centimetre. If you measure 5 marks after 2 centimetres it will be 2.5 centimetres or 2.5 into 10 millimetres that is equal to 25 millimetres. Here in the given scale arrow is given at the 9th mark after 6 centimetres so it will be 6.9 centimetres or 6.9 into 10 millimetres that is equal to 69 millimetres. This is the required answer. This completes our session. Hope you enjoyed this session.