Question

Mr. Maddox asked four students to create a number line to help find the sum of the fractions.

Negative StartFraction 7 over 10 EndFraction + StartFraction 4 over 10 EndFraction

Which number line would be best to find this sum?
A number line going from Negative StartFraction 8 over 10 EndFraction to 0 in increments of StartFraction 1 over 10 EndFraction

A number line going from Negative StartFraction 3 over 10 EndFraction to positive StartFraction 3 over 10 EndFraction in increments of StartFraction 1 over 10 EndFraction

A number line going from StartFraction 4 over 10 EndFraction to StartFraction 11 over 10 EndFraction in increments of StartFraction 1 over 10 EndFraction

A number line going from 0 to StartFraction 15 over 10 EndFraction in increments of StartFraction 1 over 10 EndFraction

Answer 1

A number line going from Negative StartFraction 8 over 10 EndFraction to 0 in increments of StartFraction 1 over 10 EndFraction

(2nd option)

Explanation:

When you add the 2 fractions together: -7/10 + 4/10 = -3/10

We need to find a number line that has -3/10 in it. The best answer choice is the 2nd option because we can go backwards to find the answer from positive 3/10 to our answer -3/10 (we are going -7 units backwards).

Answer 2

First choice

Explanation:

Sum of fractions:

• -7/10 + 4/10= - 3/10

the interval required on the line from the left of - 7/10 to the right of -3/10

Which number line would be best to find this sum?

-8/10 to 0

• yes, this is good as covers the interval from -7/10 to - 3/10

-3/10 to 3/10

• no, it doesn't include the left half of required section

4/10 to 11/10

• no, it doesn't include the required interval

0 to 15/10

• no, it doesn't include the required interval