Number & Algebra
Which number is a prime number?
A. 21
B. 29
C. 35
D. 39
Answer: 29
Reason:
29 only has two factors: 1 and 29
Which unit would be most suitable for measuring the mass of an apple?
A. g
B. kg
C. t
D. km
Answer: A. grams
Which event is impossible?
A. Rolling a 3 on a six-sided die
B. Rolling a 9 on a six-sided die
C. Rolling an even number
D. Rolling a number less than 6
Answer: B. Rolling a 9
Which is greater?
0.6 or 55%?
Answer: 0.6
Reason:
0.6 = 60%
60% > 55%
You have 10 fingers.
If you have 5 people with you, how many fingers are there altogether?
Answer: 10 × 5 = 50
Calculate:
4.95 - 1.36
Answer: 3.59
Convert:
1.5 kg = ____ g
Answer: 1 500 g
Put these in order from least likely to most likely:
certain, impossible, likely, unlikely, even chance
Impossible → Unlikely → Even chance → Likely → Certain
A shape is flipped over a mirror line.
What transformation has occurred?
Answer: Reflection
I am greater than 20 but less than 30.
I am even.
I am divisible by 3.
What am I?
Answer: 24
Reason:
Even numbers between 20 and 30:
22, 24, 26, 28
Only 24 is divisible by 3.
Complete:
¼ = ____ = ____%
Answer: ¼ = 0.25 = 25%
A shape slides 5 squares to the right without turning.
What transformation is this?
Answer: Translation
A fair six-sided die is rolled 60 times.
How many times would you expect to roll a 6?
Answer: 10 times
Reason:
Probability = 1/6
1 x 10 = 10
6 x 10 = 60
Therefore, 10/60!
A parcel weighs 2.75 kg.
You add an item weighing 320 g.
The maximum allowed mass is 3 kg.
Can you add it?
Answer: No, it would weigh 3.07 kg, which is 70 g over the limit.
Reason:
320 g = 0.32 kg
2.75 + 0.32 = 3.07 kg
3.07 kg > 3 kg
A pizza is cut into 8 equal slices.
You eat 3.
What percentage of the pizza did you eat?
Answer: 37.5%
Reason:
3/8 = 0.375
0.375 × 100 = 37.5%
Calculate:
2 419 ÷ 7
Answer: 345 r4
A box weighs 1.6 kg and another weighs 450 g.
What is their combined mass in kilograms?
Answer: 2.05 kg
How many times are you expected to roll a 6 if you roll a 6-sided die 78 times?
Answer: 14!
Reason: 78/6 = 14
A student says:
"0.4 is smaller than 35% because 4 is smaller than 35."
Are they correct?
Answer: No. 0.4 = 40%, so it is greater than 35%.
You have $20 and went to Coles bought the following items:
Punnet of strawberries = $2.50
2x Cadbury blocks = $6.50
Coconut water = $3
How much money do you have left?
Answer: $8
Reason:
2.50 + 6.50 + 3 = $12
20 − 12 = $8
A school has 450 stickers.
Each gift bag needs 18 stickers.
They want to make 24 gift bags.
Will they have enough stickers? How many will be left?
Answer: Yes they have enough and will have 18 stickers left!
Reason: 18 x 24 = 432
450 - 432 = 18
A shape is rotated 90° clockwise around a fixed point. Does its size change? Explain why or why not.
No. A rotation changes the position/orientation of a shape but does not change its size or shape.
(Does anyone know what it's called when the shape becomes bigger/larger?)
How many times are you expected to roll an 8 using a 6-sided die if you roll it 372 times?
0
A fair die is rolled 30 times.
You expect each number to appear 5 times.
The actual results are:
1 → 4
2 → 7
3 → 3
4 → 6
5 → 5
6 → 5
A student says:
"The experiment must have been wrong because the numbers aren't all 5."
Is the student correct?
No, the expected frequency is 5 but actual results can be different because chance experiments are random.
I'm between 40 and 60.
I'm an odd number.
I'm also a composite number.
I'm divisible by 3.
My digits add to 9.
What number am I?
Answer: 45
Reason:
45 → odd
45 is composite
45 ÷ 3 = 15
4 + 5 = 9