#
Problem
of the Week

Problem
A and Solution

Creating
an Art Kit

## Problem

A teacher at Sioux Mountain School wants to purchase items for art
kits to be used in their classroom. Below is a list of the items in one
kit, along with the price for each item. All prices include tax.

Pencil crayons |
\(\$1.75\) |

Sketch book |
\(\$2.25\) |

Watercolour paints |
\(\$3.15\) |

Glue |
\(\$1.10\) |

Scissors |
\(\$1.70\) |

If the teacher has a budget of \(\$80\) for art supplies, then estimate how
many kits they can make. Justify your answer.

## Solution

One way to estimate how much each kit will cost is to round the price
of each item to the nearest dollar:

Pencil crayons |
\(\$2\) |

Sketch book |
\(\$2\) |

Watercolour paints |
\(\$3\) |

Glue |
\(\$1\) |

Scissors |
\(\$2\) |

Thus, each art kit will cost approximately \(\$2 + \$2 + \$3 + \$1 + \$2 = \$10\).

With a budget of \(\$80\) and since
\(80 \div 10 = 8\), we estimate they
can make \(8\) art kits.

**Teacher’s Notes**

When we use estimation we need to realize that our estimated result
is an approximation and not an absolute guarantee of a correct answer.
We should always consider a margin of error for our estimations.

For example, in this problem if you calculate the actual cost of an
art kit, it comes to: \[1.75 + 2.25 + 3.15 +
1.10 + 1.70 = \$9.95\]

In this case, our estimation gave us the actual number of art kits
that the teacher can purchase. However, if the cost of the paints was
actually \(\$3.25\), instead of \(\$3.15\), then the actual cost of an art
kit would be \(\$10.05\), but our
estimate would still be \(\$10\). This
is a reasonable estimation, but the actual cost means the teacher does
not have the budget for \(8\) kits, but
rather for only \(7\) kits.

Since we used estimation to predict the number of kits that could be
purchased, it would be more accurate to give an answer of \(8\) kits, plus or minus \(1\) kit. This factors in the margin of
error.