Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to find the greatest and least possible slope.

### Hint

What creates a large (or small) slope?

### Answer

Greatest: 8

Least: -8

Least: -8

Source: Dane Ehlert

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to find the greatest and least possible slope.

What creates a large (or small) slope?

Greatest: 8

Least: -8

Least: -8

Source: Dane Ehlert

Tags 8.EE.6b Dane Ehlert DOK 2: Skill / Concept

Directions: Using the digits 1 to 9 at most twice each, make the sum of …

I can make a slope of 8 (which is larger than 7/3) using (2,1) & (3,9). Similarly with the smallest.

My students came up with 8 and -8 today as well!

Great catch you two! The correct solution has been updated, thanks!

How did you get the lowest slope

As I look at this, I wonder if we should consider 8 and -8 the same slope. One just being a positive and the other negative. They both have the same steepness. I was thinking 8 and 1/8. I am going to change the directions to read, Create a slope with the greatest steepness and one that is the least steep. Wondering what you all think…

Very interesting Jeanmarie. I think it highlights the mathematical precision issues with “biggest and smallest” and I really like your version. Thanks so much for adding it to the conversation.

I did the same thing Jeanmarie! I think there are more meaningful conversations around the fact that the kids that found 8 and -8 are both correct because they have the same steepness!

(0,-8) (1,9)

good but there is no 0 allowed in this question

Also, no negative numbers. We get the negative by the direction we subtract to get the slope.

Can you explain how you did this?