Chapter 11 — Filling and Lifting

The chapter covers two main topics: capacity (how much a container can hold) and weight (how heavy an object is). Children compare liquids in different vessels and compare the weight of everyday objects using a pan-balance.

The chapter introduces the litre as the standard unit for measuring liquids. It also introduces half litre and quarter litre, and children learn that 2 half-litre mugs equal 1 litre and 4 quarter-litre glasses equal 1 litre.

Children pour the contents of differently shaped glasses into same-sized glasses placed side by side. The glass whose liquid reaches the highest level holds the most.

A 1-litre bottle is used as the measuring tool. Children pour water from it into various vessels like a jug, glass, and bowl to find out whether each vessel holds more than, less than, or exactly 1 litre.

Weight is first explored by having children hold two different objects in their two hands and observing which hand goes lower. This is then extended to using a simple pan-balance to compare and measure objects.

Children use coins or unused erasers to balance lighter objects on a pan-balance. For slightly heavier objects they use a matchbox filled with sand as a non-standard weight unit.

The kilogram (kg) is introduced as the standard unit of weight. A 1 kg salt packet is suggested as a handy reference object that children can find at home.

The chapter covers half kilogram and quarter kilogram. Children are encouraged to find objects at home that are about half a kilogram or a quarter of a kilogram and verify using the 1 kg salt packet.

Three balls look the same in size but one is heavier and two are equal in weight. Children must figure out which is the heavy ball using a pan-balance and no other weights, and they are challenged to do it in just one weighing.

Knowing standard units like litres and kilograms helps people measure and compare quantities accurately. The chapter shows a real-life example of a milkman using a measuring cup to give the correct amount of milk each day.

The chapter mentions that making one 1-litre single-use plastic water bottle requires about 5 litres of water, and that using a personal glass or reusable bottle wastes less water.

Children can collect three vessels of different sizes, guess how many small bowls fill a glass or how many glasses fill a bottle, then verify by pouring water. They can also find 1 kg packets at home and use them to guess the weight of other objects.