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Rational Numbers — Chapter Test

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Q1
Which property does a × b = b × a show?
Changing the order without changing the product is the commutative property.
Q2
The additive inverse of −7/9 is ___ ?
−7/9 + 7/9 = 0, so the inverse is 7/9.
Q3
The mean of two rational numbers always lies ___ them.
The mean lies halfway between the two numbers.
Q4
The multiplicative identity for rational numbers is ___ ?
Multiplying by 1 changes nothing.
Q5
What is the multiplicative inverse of ⅗?
⅗ × 5/3 = 1, so the reciprocal is 5/3.
Q6
Find a rational number between ½ and ¾.
(½ + ¾) ÷ 2 = 5/8.
Q7
What is ½ + (−⅓)?
3/6 − 2/6 = 1/6.
Q8
What is (−⅔) × ¾?
(−6)/(12) = −½.
Q9
What is the mean of ¼ and ¾?
(¼ + ¾) ÷ 2 = 1 ÷ 2 = ½.
Q10
The additive inverse of 0 is ___ ?
0 + 0 = 0, so its additive inverse is 0.
Q11
A bowl has ½ kg of rice and ¾ kg is added. How much is there now?
½ + ¾ = 5/4 = 1¼ kg.
Q12
A rope piece is ¾ m long. How long are 4 such pieces?
¾ × 4 = 3 m.
Q13
Find a rational number between ⅓ and ½.
(⅓ + ½) ÷ 2 = (5/6) ÷ 2 = 5/12.
Q14
What is the reciprocal of −¾?
−¾ × (−4/3) = 1, so the reciprocal is −4/3.
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