Mrs. Jensen opened a box of 20 pencils. She threw out 1 broken pencil and kept the rest. The letter $k$ stands for the number of pencils she kept. We need to find the equation that can be used to find $k$.

1. Problem Description

Mrs. Jensen opened a box of 20 pencils. She threw out 1 broken pencil and kept the rest. The letter $k$ stands for the number of pencils she kept. We need to find the equation that can be used to find $k$.

2. Solution Steps

The total number of pencils Mrs. Jensen had initially was

2

0. She threw out 1 pencil.

Therefore, the number of pencils she kept is the total number of pencils minus the number of pencils she threw away.

The number of pencils she kept is represented by $k$.

So, the equation to find $k$ is:

$k$ = Total number of pencils - Number of pencils thrown away

$k = 20 - 1$

3. Final Answer

$20 - 1 = k$