Mass

6.2  Mass

Convert Units of Mass

1 kg = 1000 g

Convert 2 kg 500 g in g.

Method:

\(2\,\text{kg}\,500\,\text{g}=\) _____ g

\(2\,\text{kg}\,500\,\text{g}\Longrightarrow\;2\,\text{kg}=2000\,\text{g} \\\quad\quad\quad\quad\Longrightarrow\;500\,\text{g}\)

\(2\,\text{kg}\,500\,\text{g}=2\,000\,\text{g}\;+\;500\,\text{g} \\\quad\quad\quad\quad=2\,500\,\text{g}\)

\(2\,\text{kg}\,500\,\text{g}=2\,500\,\text{g}\)

 

Addition of Mass

Mathematical sentence: \(112\;\text{kg}\;+\;365\;\text{kg}\;+\;78\;\text{kg}=\) _____ kg

Method:

 \(\begin{array} {rr} \small{\color{red}{1}}\space \small{\color{red}{1}}\quad\quad\quad\, \\\space\space1\space1\space2\quad\text{kg} \\\space\space3\space6\space5\quad\text{kg} \\+\quad\space7\space8\quad\text{kg} \\\hline\space\space5\space5\space5\quad\text{kg}\\\hline \end{array}\)

 

Substraction of Mass

Hen

2 350 g

Rooster

350 g

How much more is the mass of hen than the mass of rooster?

Mathematical sentence\(2\,350\;\text{g}\;-\;350\;\text{g}=\) _____ g

Method:

\(\begin{array} {rr} \\\;2\;3\;5\;0\quad\text{g} \\-\;\;\;\;3\;5\;0\quad\text{g} \\\hline\;\;\;2\;0\;0\;0\quad\text{g} \\\hline \end{array}\)

So, the mass of hen is 2 000 g more than the mass of rooster.

 

Multiplication of Mass

One packet of rice has a mass of 15 kg. Calculate the mass of 8 simillar packets of rice.

Mathematical sentence\(8\;\times\;15\,\text{kg}=\)  _____ kg

Method:

\(\begin{array} {rr} \small{\color{red}{4}}\quad\quad\;\, \\\;1\;5\;\;\text{kg} \\\times\;\;\;\quad8\quad\;\,\, \\\hline\;\;1\;2\;0\;\;\text{kg}\\\hline \end{array}\)

So, the mass of 8 simillar packets of rice is 120 kg.

 

Division of Mass

The mass of 4 toy train is 600 g. What is the mass of one of the toy train?

Mathematical sentence\(600\;\text{g}\;\div\;4=\) _____ g

Method:

\(\;\;\;1\,5\,0\;\;\text{g} \\4\overline{\smash{)}6\,0\,0\;\;\text{g}} \\\,\underline{-4}\downarrow \\\;\;\,2\,0 \\\,\underline{-2\,0}\downarrow \\\;\;\;\;\;0\,0 \\\;\;\,\underline{-\;\;\;0} \\\;\;\;\;\;\;\;\;\,0\)

So, the mass of one of the toy train is 150 g.