Basic Operation Involving Time

4.3 Basic Operations Involving Time

We will learn how to solve problems involving addition and substraction of time. There are various methods to solve them. The methods shown below are not restricted to specefic uses.


Addition of Time in Frractions and Decimals
Hours and Minutes

We have to convert it to equivalent fractions!

Convert the final answer to minutes.



Days and Hours

We can seperate whole numbers from its fractions.

Convert to unit hours.

Years and Months

Decades and Years

Improper fractions must be converted to proper fractions.

Seperates decades and years to add the decades.

Convert decades to years. Then, add both of the years.

Centuries and Decades

Convert the fractions to centuries.

Convert 0.37 centuries to decades.


Centuries and Years

Convert to needed unit.

Convert 61.37 centuries to years.

Substraction of Time in Fractions and Decimals
Hours and Minutes

We need to have equivalent fractions to substract.

We can convert to minutes first for easier operation.

Days and Hours

Equalise the denominator.

Years and Months

Convert the fractions to months.

We can convert the decimals to months first.

Decades and Years

Convert to years.

Convert 8.1 decades to decades and years.

Centuries and Decades

Convert to decades.

Centuries and Years