Misconception 3: Reading Scales

What misconceptions occur when children are reading scales?

Ø  Some children pick the container up and fail to keep it vertical when reading the scale

Ø  Some children read the scale by looking at the value at the top of the meniscus (curve in the surface of a liquid, produced in response to the surface of the container or another object. It can be either concave or convex)

Ø  some children read the scale from different heights so that parallax (difference of orientation of an object viewed along two different lines of sight) occurs. Some pupils do not understand the measurement between marked divisions on a scale.

v  How can we facilitate children’s learning in this area?

v  Teachers need to ensure that children have the opportunity to use and read a range of measuring scales on real containers with different scales in different orientations. Encourage children to make sure that they have the container on a flat surface and are looking at the liquid at the same level. They must ensure that they are looking at the base of the meniscus. Encouraging children to estimate liquid volume before measuring will support some of these activities.

v  The Primary National Strategy Interactive Teaching Programme Measuring Cylinder is a useful tool for demonstrating reading a scale alongside practical activities.      

            This Interactive Teaching Programme Measuring Cylinder ( ITP) allows you to control two taps that pour a liquid in and out of a measuring cylinder. You can set the scale on the cylinder to a maximum of 50, 100, 200, 500 or 1000 units and the scale interval to 1, 2, 5 or 10 units. You can simply turn the taps on and off and ask questions that involve prediction, addition and subtraction. Using the inlet and outlet controls to set the amount of liquid to pour in and out of the cylinder offers the opportunity for the introduction of multiplication (repeated addition) and division (repeated subtraction) too. A marker can be set to indicate an early quantity.

        The ITP can be used to explore and consolidate the interpretation and reading of scales, mental calculation strategies and methods of recording. Using different scales can support children’s estimation skills and provides a context for problem solving involving capacity and volume.

Hide or show the numbers on the scale.

Show or hide the outlet pipe and controls

Show or hide the reading of the amount of liquid in the measuring cylinder.

Inlet and outlet controls can be set using the pointers.

This is set to let 33 units of liquid flow out of the measuring cylinder once the 

tap is turned.

Based on the several of misconceptions in the area of volume and capacity above, teacher should be applied them to making activities by teaching aids for more easier to especially  Year Two students to help them understand better. It has provided for high  achiever and low achiever students.