Question 1: Products (2 points)
- Different signs: \(-63\).
- Same signs: \(66\).
Scoring: 1 point for each correct product.
Question 2: Product from a Number Line (2 points)
Three jumps, each \(4\) units to the left.
\(3 \times (-4) = -12\)
Scoring: 1 point for the correct multiplication \(3 \times (-4)\), 1 point for \(-12\).
Question 3: Quotients (2 points)
- Different signs: \(-9\).
- Same signs: \(8\).
Scoring: 1 point for each correct quotient.
Question 4: Zero in Division (2 points)
- \(0 : (-9) = \)\(0\), since \((-9) \cdot 0 = 0\).
- \(6 : 0 = r\) would require \(0 \cdot r = 6\). No number multiplied by \(0\) gives \(6\), so the quotient is undefined.
Scoring: 1 point for part (a). 1 point for part (b) for explaining that no number \(r\) satisfies \(0 \cdot r = 6\).
Question 5: Decimals and Fractions (2 points)
- \(0.5 \times 8.4 = 4.2\), negative: \(-4.2\).
- \(\frac{18}{30} = \)\(\frac{3}{5}\), positive because both factors are negative.
Scoring: 1 point for each correct product. Accept \(0.6\) for part (b).
Question 6: A Pattern of Products (3 points)
- \((-5)(-1) = 5\) and \((-5)(-2) = 10\).
- Each product increases by \(5\).
- The products continue upward past \(0\) into positive values, so a negative times a negative is positive.
Scoring: 1 point for each part.
Question 7: Falling Temperature (3 points)
- \(6 \times (-4) = -24\), so \(-24^{\circ}\text{F}\).
- \(10 + (-24) = -14\), so \(-14^{\circ}\text{F}\).
- \(-24 : 6 = \)\(-4^{\circ}\text{F}\) per hour.
Scoring: 1 point for each part.
Question 8: Equivalent Forms (2 points)
- All three equal \(-3\).
- \(\frac{15}{-3} = \frac{-15}{3} = \)\(-5\).
Scoring: 1 point for part (a) with all three values correct. 1 point for part (b), giving the equivalent form and the value.
Question 9: Three Factors (2 points)
\((-2)(-5) = 10\). Then \(10 \cdot (-3) = -30\). Finally \(-30 : 6 = \)\(-5\).
Scoring: 1 point for a correct partial product (\(10\) or \(-30\)), 1 point for the final answer \(-5\).
20 points

See every chapter on the Grade 7 math page.

