Download 6T Maths Homework - 3/3/17 Order of Operations

6T Maths Homework - 3/3/17
Order of Operations
(BracketsOrderDivideMultiplyAddSubtract) tells us the order in which calculations in a sum should be done.
1(a)
40 − 10 ÷ 2
Emma works out
Her answer is 15
The correct answer is 35
Explain the mistake that Emma has made.
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Put +, −, × or ÷ in each of the following to make them true.
(b)
2 (a)
Work out the answer.
2
(b)
+
(16
÷
2)
+
6
=
....................
Put brackets in the calculation below to make it correct.
2
+
16
÷
2
+
6
=
4
3) Write in the boxes what the missing numbers could be.
+
+
=
×
15
=
–
×
4(a)
+
Write the answers.
(4 + 2) × 3 = ........................
4 + (2 × 3) = ........................
(b)
Work out the answer to
(2 + 4) × (6 + 3 + 1)
(c)
4
Put brackets in the calculation to make the answer 50
+
5
+
1
×
5
=
=
15
15
15
(d)
4
Now put brackets in the calculation to make the answer 34
+
5(a)
5
+
1
×
5
List the first five multiples of 11
Answer _____; _____; _____; _____; _____;
(b)
Is 109 a multiple of 11?
Give a reason for your answer.
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Factors, Multiples, Squares, Cubes and Primes
Factor - A number that divides exactly into another number
Multiple - A number that may be divided by another number a certain number of times without a remainder
Square Number - The answer when an integer has been multiplied by itself
Cube Number - The answer when an integer is multiplied by itself and by itself again.
Prime - A number that has exactly 2 factors, 1 and itself
6 (a)
What is the highest common factor (HCF) of 18 and 24?
Answer ______________________________
(b)
The least common multiple (LCM) of two numbers is 20
Give an example of what the numbers could be.
Answer ____________ and ______________
7)Three prime numbers add up to 30
Give an example of what the three prime numbers could be.
Answer ______ and ________ and ________
8) A number has eight factors.
Five of the factors are 1, 2, 3, 5 and 10.
What are the other three factors?
Answer ______ and ________ and ________
9) What is the only number that is
1 more than a square number and 1 less than a cube number?
Answer ______________________________
10) Write down all the numbers which are multiples of 3
and
Answer ______________________________
11) 70 written as the product of prime factors is
(a)
2×5×7
Write 84 as the product of prime factors.
Answer _____________________________
(b)
Work out the highest common factor (HCF) of 84 and 70
Answer _____________________________
(c)
Work out the lowest common multiple (LCM) of 84 and 70
Answer _____________________________
12) Write down a number which is
•
a multiple of 4
•
a factor of 400 •
not 4 or 400
13) Here is a list of numbers.
6
9
11
From the list, write down
(a)
the multiple of 12
27
30
36
90
factors of 45
(b)
the two factors of 30
(c)
the prime number
(d)
the cube number
14) Mark is thinking of a square number whose digits add up to seven.
Write down two numbers he could be thinking of.
Answer ____________ and _____________
15) The word ‘prime’ spelt backwards is ‘emirp’.
An emirp is a prime number that makes a different prime number when its digits are reversed.
For example, 13 and 31 are a pair of emirps.
(a)
Write down another pair of emirps between 10 and 100
Answer _____________________________
(b)
Explain why 19 and 91 are not a pair of emirps.
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16) The product of two whole numbers is an odd number.
Explain why the sum of the two numbers must be an even number.
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17) Three positive whole numbers add up to 34
One of the numbers is a multiple of 9
The other two numbers are equal.
What are the three numbers?
Answer _________ , _________ , _________
18) Lena’s phone number has six digits. They are all different. She remembers it as three 2-digit numbers.
The first 2-digit number is a factor of 118
The second 2-digit number is a prime number less than twenty.
The third 2-digit number is a square number which is not a cube number.
What is her phone number?
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Homework due in by Wednesday 8th March