In our daily lives, we must measure a variety of things. We measure things such as distance, length, weight, time, and temperature. All of the items we measure are counted using a unit. The smallest quantity of something that we can measure is called a unit. Let us consider the things that can be measured.

Measurement of Length 

The term "length" refers to how long an object is. People used to measure length by using their own body parts in the past. The units used to measure lengths include handspan, cubit, and foot span. Measurements of length using body parts are inexact and vary from person to person, these are referred to as non-standard units for measuring length.

For example: Your foot span will be different from your grandfather's foot span when measuring length.

In today's world, length is measured in standard units. A metre is the standard unit of length. Smaller lengths are measured in centimetres, millimetres, or metres, and are denoted by the letters cm, mm, and m. Longer distances are measured in kilometres and written as km. Rulers, measuring tape, and a metre rod are used to determine length.

Measurement of Mass 

The mass of anything is a measure of how heavy or light it is. The mass of various objects vary. Lighter objects are measured in milligrams or grams. They are denoted by the letters mg and g, respectively. The mass of heavier objects is expressed in kilogrammes, which is represented as kg. A weighting balance and an electronic balance are used to determine mass.

Now let us look at how the mass units are related to one another.

1000 milligrams = 1 gram
1000 grams = 1 kilogram

Next Generation Science Standards 

3-PS2-1. 

3-PS2-2. 

3-PS2-3. 

3-PS2-4. 

K.PS2.A (3-PS2-1); K.PS2.B (3-PS2-1); K.PS3.C (3-PS2-1); K.ETS1.A (3-PS2-4); 1.ESS1.A (3-PS2-2); 4.PS4.A (3-PS2-2); 4.ETS1.A (3- PS2-4); 5.PS2.B (3-PS2-1); MS.PS2.A (3-PS2-1),(3-PS2-2); MS.PS2.B (3-PS2-3),(3-PS2-4); MS.ESS1.B (3-PS2-1),(3-PS2-2); MS.ESS2.C (3-PS2-1)

Common Core State Standards Connections: 

ELA/Literacy – RI.3.1 (3-PS2-1),(3-PS2-3) RI.3.3 (3-PS2-3) RI.3.8 (3-PS2-3) W.3.7 (3-PS2-1),(3-PS2-2) W.3.8 (3-PS2- 1),(3-PS2-2) SL.3.3 (3-PS2-3) Mathematics – MP.2 (3-PS2-1) MP.5 (3-PS2-1) 3.MD.A.2