Download Parenting a Gifted Child

Mathematics: Number problems
1. Look at the symbols and numbers in the chart below. Now choose a word from the box that
matches the symbols and numbers. Write the word in the ‘Word’ column.
Symbol or number
Definition
Word
2, 4, 6, 8, 10, 12, 14, 15
Numbers you can divide by 2
even number
Numbers you cannot divide
1, 3, 5, 7, 9, 11, 13, 15, 17
by 2
0.5, 0.75, 1, 2, 3, 8, 22
A number bigger than 0
–10, –2, –5, –7.5
A number less than 0
⅓, ½
A number only divisible by 1
2, 3, 7, 11
or itself
20%, 50%, 75%
%
2:1, 4:1, 6:1
:
 ( e.g. 2 + 3 = 7  )
Not correct, not right
7 + 10 = 17
The total when you add
The ____ of 7 and 10 is 17
25 + 30 = 55
numbers together
The ___ of 25 and 30 is 55
32
Bigger than
3 is _______ than 2
79
Smaller than
7 is _______ than 9
The same as
½ is the ______ of 50%
½ = 50%
¼ = 0.25
4
/8
½
The _______
/12  ¾
9
12 is a ____ of 2, 3
2 and 3 are
and 4
________ of 6
4
of /8 is ½
The product (×) of a number
12 is a _______of 2, 3 and
and any other whole number
4
A smaller number that divides
2 is a ______ of 6
exactly into a bigger number
3 is a ______ of 6
even number
factor
odd number
multiple
simplest form
negative number
equivalent
fraction
prime number
percentage
positive number
wrong
sum
less
greater
ratio
P. 1 of 6
Copyright © HKAGE. All rights reserved.
2. Decide if the following are true or false.
(a) 20, 30, 8, and 212 are even numbers.
(b) 9, 11, 121 and 15 are odd numbers.
(c) 2, 7, and 11 are prime numbers.
(d) 3, 7, 13 and 14 are prime numbers.
(e) The sum of 7 and 5 is 12.
(f) The sum of 2 and 3 is 6.
(g) 100 is a multiple of 5 and 10 and 20.
(h) 75% expressed as a fraction is ½ .
(i) If there are 6 boys and 3 girls in a class, this is a ratio of 2:1.
(j) ¼ is greater than 20%.
3. Look at the following number problems and write the answers on your sheet.
3.1.
Think of a number
(a)
Henry thinks of a number between 1 and 20.
He thinks of the number 12.
For each question below, tick (
) Yes or No for Henry’s number.
Yes
No
Is it an even number?
Is it a multiple of 3?
Is it a factor of 18?
1 mark
(b)
Ashraf also thinks of a number between 1 and 20.
The table shows information about his number.
Yes
Is it an even number?
Is it a multiple of 3?
Is it a factor of 18?
What is Ashraf’s number?
P. 2 of 6
Copyright © HKAGE. All rights reserved.
No
.............
1 mark
3.2.
Making ten
Write two numbers that add up to 10.
One of the numbers must be positive.
The other number must be negative.
+
=
10
1 mark
3.3.
Adding odd
James says:
Adding two odd numbers always gives an odd number answer.
Give an example to show that James is wrong.
1 mark
P. 3 of 6
Copyright © HKAGE. All rights reserved.
3.4.
Goldbach
A famous mathematician claimed that:
Every even number greater than 4 can be
written as the sum of a pair of prime numbers.
For example:
8 can be written as the sum of 3 and 5, and
3 and 5 are both prime numbers.
(a)
Write a pair of prime numbers that sum to 16
............. and .............
1 mark
Now write a different pair of prime numbers that sum to 16
............. and .............
1 mark
(b)
Now choose an even number that is greater than 16, then write a pair of prime numbers that
sum to your even number.
Complete the sentence below.
The even number ............. can be written as
the sum of the prime numbers ............. and .............
1 mark
P. 4 of 6
Copyright © HKAGE. All rights reserved.
3.5.
Cards for fractions
Here are six number cards.
2
(a)
4
6
8
10
12
Choose two of these six cards to
make a fraction that is equivalent to
1
3
1 mark
(b)
Choose two of these six cards to
make a fraction that is greater than
1
but less than 1
2
1 mark
P. 5 of 6
Copyright © HKAGE. All rights reserved.
3.6.
Grey and black designs
(a)
In this design, the ratio of grey to black is 3 : 1
What percentage of the design is black?
............................%
1 mark
(b)
In this design, 60% is grey and the rest is black.
What is the ratio of grey to black?
Write your ratio in its simplest form.
............. : .............
2 marks
P. 6 of 6
Copyright © HKAGE. All rights reserved.