# Actually Applicable Application Problems and Brainteasers/Materials for Projects: Yarn for Flat Projects

## Overview

Knowing how much yarn is needed to complete a project is important if you are making something for your own use or as a gift, to make sure you buy enough yarn, and if you are making the items to sell, to make sure you are charging enough considering the cost of materials.

## General Method

1. Make a swatch.
• Usually this will be rectangular but it can vary depending on the project.
2. Use a high-enough precision scale to weigh the swatch.
3. Calculate the swatch's area.
4. Divide the swatch's weight by its area to find the weight of yarn needed to make each square inch.
5. Multiply the weight of yarn per square inch by the number of square inches in the project to find the total weight of yarn needed for the project.
6. If necessary, do a unit conversion to get the amount of yarn into a convenient unit.

## Problems

How much yarn would you need to make a scarf 10 inches wide and 4 feet long?