Mixed operations involving Addition and Substraction

 
2.5  Mixed operations involving Addition and Substraction
There are various methods for solving mixed operations involving appropriate addition and subtraction of numbers up to 10 000
 
Examples of mixed operation questions and solutions involving addition and subtraction

5 640 men and 3 290 women participated in the Merdeka Day poster drawing competition. However, 1 230 of the participants were ill and could not attend the day of the competition. So, how many contestants competed during the event day?

Mathematical sentence: \(5\,640\space+\space3\,290\space-\space1\,230=\space\underline{\quad\quad}\)

 

METHOD 1:

\(\begin{array} {rr} \space\space\small{\color{green}{1}}\space\space\space \quad \\5\,\space\space6\space4\space0 \\+\quad\space3\,\space\space2\space9\space0 \\\hline\space8\,\space\space9\space3\space0 \\-\quad\space1\,\space\space2\space3\space0 \\\hline\space7\,\space\space7\space0\space0 \\\hline \end{array}\)

 
 

METHOD 2: 

\(\begin{array} {rr} \space\space\small{\color{green}{1}}\space\space\space \quad \\5\,\space\space6\space4\space0 \\+\quad\space3\,\space\space2\space9\space0 \\\hline\space8\,\space\space9\space3\space0 \\\hline \end{array}\)             \(\begin{array} {rr} \quad \\8\,\space\space9\space3\space0 \\-\quad\space1\,\space\space2\space3\space0 \\\hline\space7\,\space\space7\space0\space0 \\\hline \end{array}\)

 
 
So, the total of contestants competed during the event day is 7 700 contestants.