The Game of Measuring
Let the child with his eye, and without a rule, measure the length of the table, of the book case, the side of the room, or the height of a door. Have him do this by eye measurement and not by guess work. Teach him to start at one end and select a point which he judges to be one foot from the end and then to advance the eye to a point one foot from that and so on, counting as he goes, "one, two, three and a half"—whatever he believes is right. Then have him take the foot rule and check his measurements accurately.
In the same manner the child should be taught to know and to be able to measure with the yard stick. With it, of course, measure larger objects, as the length of the house, the width of the porch, the distance from the house to the sidewalk, the width of the street, the height of the shed, etc. Teach the child to recognize the distance of a block, a half mile or a mile, and the size of an acre.
Unless you have had some practice in work of this kind, you will find yourself busy keeping ahead of the child. You can get excellent practice and development which will be of value to you, by entering into these exercises. Make it a point to become thoroughly interested in the work yourself, as it will insure continuation and increased good for the child. Remember the interest increasing value of competition.
While training the child's eye to measure, excellent practice will be found in determining comparative length of lines. The illustrations below will show some of the ways in which the lines can be made confusing. The child should be given enough drill in this exercise so that he learns to judge the things as they are, and not as they seem.
Have him look at Figure 1 and decide which is the longer line, a side of the square B or the diameter of the circle A. Then have him measure carefully.
In like manner compare the height of the two rectangles in Figure 2. Which line is longest in Figure 3—AB, CB, or BD? Which vertical lines are tallest in Figure 4—those between AB or BC?
In Figure 5 which line is longest, A, B or C?
Good practice can be had in judging the size of boxes by comparing the length of one box with the width of another, or any similar measurements. In each case the measurements should actually be made so that all error can be corrected.
In the same way practice with size and thickness of books. Let the child estimate them by inches so that he learns to determine accurately the difference in thickness. The carpenter can readily tell the full inch board from the seven-eights boards by looking at it or by feeling. His ability to do this is the result of practice.
The size of type is a good thing to practice with, as the irregular outlines of the type make it quite confusing. A sample book of type can be gotten from any printer. From this the child can also be taught to become familiar with the common type faces. This knowledge he can use to good advantage in later years.
The child should be taught a definite length of step for the purpose of measurement. In proportion to his size he can learn to step off two feet or a yard. He should also know the length in inches of his shoe for the purpose of checking shorter measurements.
Have the child know his height and estimate the height of trees, buildings, etc. These estimates can be checked by computing the proportion of the length of the shadow thrown by the tree and using the proportion.
Example—If the child is five feet tall and his shadow measures three feet, the shadow is three-fifths of his height. If the shadow of the tree measures fifteen feet, the height of the tree is twenty-five feet.