Question

Tori, Alaina, Manuel, and Nelish each attempted to plot the point Negative 1 and one-fifth on a number line.


Tori A number line going from negative 2 to positive 2 in increments of 1. There are 5 equal spaces between each number. A point is 1 mark to the left of negative 1.

Alaina A number line going from negative 2 to positive 2 in increments of 1. There are 5 equal spaces between each number. A point is 1 mark to the right of negative 1.

Manuel A number line going from negative 2 to positive 2 in increments of 1. There are 10 equal spaces between each number. A point is 2 marks to the right of negative 2.

Nelish A number line going from negative 2 to positive 2 in increments of 1. There are 10 equal spaces between each number. A point is 2 marks to the right of 1.

Who plotted the point correctly?
Alaina
Manuel
Tori
Nelish

Answer 1

To determine who plotted the point correctly, let's first understand the location of the point Negative 1 and one-fifth (−1.2) on a number line.

1. The point −1 is located to the left of zero at the position of -1.
2. The point −1 and one-fifth (−1.2) is to the left of -1, specifically 1/5 or 0.2 units to the left of -1, which places it at -1.2.

Now let's evaluate each person's plotting:

- **Tori**: Plotted a point 1 mark to the left of -1. With 5 equal spaces between each number on her number line (marks at -1.2, -1.4, -1.6, etc.), one mark to the left of -1 would place it at -1.2, which is correct.

- **Alaina**: Plotted a point 1 mark to the right of -1. This would place the point at -0.8, which is incorrect.

- **Manuel**: Plotted a point 2 marks to the right of -2. Since there are 10 equal spaces between each number, this means he is placing the point at -1.8 (moving right from -2), which is incorrect.

- **Nelish**: Plotted a point 2 marks to the right of 1. This places it at 3 which is also incorrect.

Thus, the only person who plotted the point correctly is **Tori**.