6.3.3 Banking with Fractions
Activity: Banking with Fractions
In the New Policy Institute survey introduced before, of the 210 young people had bank accounts. Of these, had overdraft protection and approximately had checkbooks.
(a) How many of the people surveyed had overdraft protection?
How many people from the group had a bank account? The word “of” often translates into multiplication and a whole number can be written as a fraction by placing it over 1. What fraction of those with bank accounts have overdraft protection?
(a) Let’s use our new knowledge of fraction multiplication. of 210 translates to .
So, we know that 126 people have bank accounts. One third of this group have overdraft protection, so .
Therefore, 42 of the people surveyed have overdraft protection.
(b) How many survey participants had checkbooks?
(b) We already know how many people have bank accounts: 126. We then need to find of this group.
We can calculate that people.
This fraction, it turns out, is an approximation. You need to interpret the results of your calculation carefully, particularly if it involves fractions of a person!
So, about 50 people have checkbooks.
In the previous activity, you might have approached the problem differently. Perhaps you found what one-fifth of the group was first by using division, and then used this portion to find three of those sets. Once you had this value, which indeed is 126 people, you could have then found the number of people with overdraft protection and checkbooks as done above.
Both approaches are valid and will give you the correct answers. Choose whichever method is easier for you.