Types of numbers
Is 14 an odd number or an even number?
Even
Write 12 a product of its prime factors.
12=22X3
Find the HCF of 18 and 24
6
Calculate: 6+4×3
18
Round 4768 to the nearest hundred.
4800
What is the square root of 36?
6
Write 30 as a product of its prime factors
30=2X3X5
Find the LCM of 8 and 12
24
Calculate: (20−8)÷3+5
9
Estimate 398+612 by rounding each number to the nearest hundred.
400+600=1000
Is 29 a prime number or a composite number? Explain how you know.
Prime because it only has 2 factors (1 and 29)
Write 84 as a product of its prime factors
84=22x3x7
Two bells ring at regular intervals. One rings every 6 minutes and the other rings every 8 minutes. If they ring together at 9:00 a.m., at what time will they next ring together?
9:24am
A student writes:
24÷6+2×3=
4+2×3=
6×3=
18
Identify the mistake and find the correct answer.
The student added before multiplying. The correct answer is 10.
Estimate 49×21
50x20
= 1000
What is the cube root of 216?
6, because 63=216
The prime factorisation of a number is 22x33. What is the number?
108
A teacher has 48 red ribbons and 60 blue ribbons. She wants to make the greatest possible number of identical sets, using all the ribbons. How many sets can she make, and how many of each colour will be in each set?
12 sets, with 4 red and 5 blue ribbons in each set
A student writes:
36÷(3+3)×2+4
=36÷6×6
=6×6
= 36
Identify the mistake and find the correct answer.
The student incorrectly added 2x4. The answer should be:
36÷(3+3)×2+4
=36÷6×2+4
=6×2+4
= 12+4
= 16
A school buys 19 notebooks at $3.95 each and 8 pens at $1.10 each. Estimate the total cost. Which answer is most reasonable: $20, $90, or $180?
$90
I am a number greater than 50 and less than 100. I am even, composite, a perfect square, and a perfect cube. What number am I? Give my square root and cube root.
64. It is even and composite, a perfect square, and a perfect cube.
The prime factorisation of 360 is 2a x 32 x 5. What is the value of a?
3.
23 x 32 x 5 =360
Your class has 84 red beads, 126 blue beads and 210 green beads. You wants to make the greatest possible number of identical craft kits, using all the beads. How many kits can be made, what will each kit contain?
42 kits. Each kit contains 2 red, 3 blue and 5 green beads.
Insert brackets to make the following true:
2+3×42−5=191
(2+3×4)2−5=191
Four friends eat at a restaurant. Their bill includes:
Estimate the total bill and estimate how much each person should pay if they divide the bill equally.
The exact bill is $44.95, so the exact share would be approximately $11.24 per person. Accept around $11