Sharks

Explanation

We will carefully read the problem looking for a key word or phrase.  Key words and phrases indicate which arithmetic operation(s) should be used to solve the problem.

Solution

In the second sentence of the problem, the key word total indicate that we should add the number of shar attacks for the years 2000 through 2007.  We can use vertical form to find the sum.

Add the digits, one column at a time, working from right to left.  To simplify the calculations, we can look for groups of two or three numbers in each column whose sum is 10.

\[ \begin{array}{r} \phantom{0}\overset{5}{\color{transparent}{\text{1}}}\phantom{0}\overset{3}{7}\phantom{0}\!9 \\ \phantom{0}6\phantom{0}\!8 \\ \phantom{0}6\phantom{0}\!2 \\ \phantom{0}5\phantom{0}\!7 \\ \phantom{0}6\phantom{0}\!5 \\ \phantom{0}6\phantom{0}\!1 \\ \phantom{0}6\phantom{0}\!3 \\ +\phantom{0}7\phantom{0}\!1 \\ \hline \phantom{0}5\phantom{0}2\phantom{0}\!6 \\ \end{array} \]

The total number of shark attacks worldwide for the years 2000 through 2007 was 526.