7th Grade Adding and Subtracting Rational Numbers Test Solutions and Scoring (PDF)

7th Grade math test solutions: Adding and Subtracting Rational Numbers – Maths PDF

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This add subtract rationals test answers for 7th Grade covers adding and subtracting rational numbers (Common Core 7.NS.A.1), with a free PDF to print.

Use this answer key and scoring guide to grade the adding rational numbers test. Each solution shows the full work, and the scoring note explains how the points are awarded. Give partial credit for correct steps even when the final answer is wrong.

Grade 7 · Common Core State Standards: 7.NS.A.1

Add subtract rationals test answers: worked solutions

Question 1 – Integer sums [2 pts]

$-14+9=-5$
$6-(-8)=6+8=14$
$-11-5=-16$
$-7+(-13)=-20$

-5, 14, -16, -20

Scoring: Half a point for each correct value (round the total up).

Question 2 – Number line model [2 pts]

Start at -3 and move 7 units right.

$-3+7=4$

The move ends at 4.

Scoring: 1 point for the correct direction and length of the move; 1 point for the sum.

Question 3 – Decimals [2 pts]

$-4.8+2.35=-2.45$
$-0.6-1.75=-2.35$

-2.45; -2.35

Scoring: 1 point for each.

Question 4 – Fractions [2 pts]

$-\frac{8}{12}+\frac{9}{12}=\frac{1}{12}$
$\frac{3}{6}+\frac{5}{6}=\frac{8}{6}=\frac{4}{3}=1\frac{1}{3}$

$\frac{1}{12}$; $1\frac{1}{3}$

Scoring: 1 point for each.

Question 5 – Distance [2 pts]

$|4-(-5)|=|9|=9$

9 units

Scoring: 1 point for the expression; 1 point for the value.

Question 6 – Additive inverse [2 pts]

The other number is the opposite of $-6.2$, which is $6.2$.

Both numbers are 6.2 units from 0 on opposite sides, so the sum is 0.

6.2

Scoring: 1 point for 6.2; 1 point for the explanation.

Question 7 – Mixed operations [2 pts]

Common denominator 12: $-\frac{9}{12}+\frac{18}{12}-\frac{8}{12}=\frac{1}{12}$

$\frac{1}{12}$

Scoring: 1 point for common denominators; 1 point for the final value.

Question 8 – Temperature story [3 pts]

$-6+15=9$°F.
$9-6=3$°F.
$3-(-6)=9$ degrees higher.

Temperatures at 9 a.m., noon and 6 p.m.

Scoring: 1 point for each part.

Question 9 – Lunch account [3 pts]

$25.00-18.75=6.25$; $6.25-12.40=-6.15$; $-6.15+20.00=13.85$.

Wednesday: overdrawn by $6.15.

Completed balances.

Scoring: 1 point for each correct balance after the first (3 points total); award all 3 points if the overdraft is also named, otherwise deduct nothing but note it.

Total score

Total

20 points

Key facts behind this add subtract rationals test answers

Key facts

Opposites add to 0: $p + (-p) = 0$.
Same signs: add sizes and keep the sign. Different signs: subtract sizes and keep the sign of the larger size.
Subtracting $q$ means adding the opposite of $q$.
$|p|$ is the distance from p to 0.
The distance between p and q on a number line is $|p – q|$.

How to use this add subtract rationals test answers

Score your test with the point values shown for each question. Then read the worked solution of every question where you lost points and note the method to review.

All Grade 7 chapters: Grade 7 math.

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