Number 1 Flashcards
True or False?
All prime numbers bigger than 5
end in 1, 3, 7, or 9
True
What is an integer?
A whole number
Can be positive, negative or zero
When should you stop listing pairs of numbers when finding factors?
When a number is repeated
True or False?
8.62 x 1000 = 862
False = 8620
780 ÷ 12
65
On a number line which way do you move to subtract?
Left
What is
Prime Factorisation?
Writing a number as its prime factors multiplied together
True or False?
The highest common factor of 30 and 45 is 15
True
When you multiply a number by 10, how many places bigger do you move the decimal point?
One
How do you find the lowest common multiple
using prime factors?
Put the prime factors in a Venn diagram,
then multiply all the numbers together in the Venn diagram
If you multiply two negative numbers together,
will the answer be positive or negative?
Positive
What should you circle in a factor tree?
Prime numbers
When you divide a number by 100,
how many places smaller do you move the decimal point?
Two
What is a square number?
A number that is made by multiplying a whole number by itself
What does the completed top line of a short division calculation show?
The final answer
How do you find the highest common factor using prime factors?
Put the prime numbers in a Venn Diagram.
Multiply the prime numbers together that are in the overlapping section
What do the letters BIDMAS stand for?
Brackets, Indices,
Division, Multiplication,
Addition, Subtraction
What is a prime number?
A number with exactly two factors.
One and itself
Is 30 a multiple of 12 ?
No
30 isn’t in the 12 times table
How would you use
38 x 24 = 912
to work out
3.8 x 2.4 ?
Because you divided the 38 by 10 and divided the 24 by 10 on the left hand side,
You need to divide the 912 by 100 on the right hand side
4.3.8 x 2.4 = 9.12
What is a factor of a number?
A number that divides into it
If you work out 1530 ÷ 10 = 153.0
what is the last step do you need to do?
Remove the decimal point and the zero after it
Is the answer to
5 - - 8
positive or negative?
Positive
5 - - 8 = 13
In the calculation
4 x 3 + 2
What should be carried out first?
The multiplication
4 x 3
Calculate
32 x 17
without a calculator
544
The prime factors that appear in both of two numbers are
2, 3, 3 and 5
What is the highest common factor of the two numbers?
90
What are the first four square numbers?
1, 4, 9, 16
How would you use
65 x 3 = 195
to work out
65 x 300
Because you multiplied the 3 by 100 on the left hand side,
You need to multiply the 195 by 100 on the right hand side
65 x 300 = 19,500
What would be the first step in working out 36 ÷ 0.15 ?
Write the division as a fraction
What is lowest common multiple?
The smallest number that is in all of the lists of multiples,
produced from the numbers in question
What is a cube number?
A number made by multiplying a whole number by itself twice.
e.g. 53 = 5 x 5 x 5 = 125
What is a highest common factor?
The biggest number that is in all the lists of factors,
that have been produced from the numbers in question
What is the first thing you should do to work out
23 x 2000 ?
Multiply 23 by 2
23 x 2000 = 46000
What is the lowest common multiple of
4 and 5 ?
20
What are the first four prime numbers?
2, 3, 5, 7
Is the answer to
-6 ÷ 3
positive or negative?
Negative
-6 ÷ 3 = -2
In the calculation
7 - 12 + 8
What should be carried out first?
The subtraction
7 - 12
When calculating 852 ÷ 3 using short division,
how would you record the result of dividing 8 by 3 in your working?
Write 2 above the line and
carry the remainder 2 to the next digit
What is a multiple of a number?
A value in a number’s times table
What is the product of prime factors for 140 ?
2 x 2 x 5 x 7
OR
22 x 5 x 7
