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Date:
R
C
H A PTE
12
Numbers to 40
PROBLEM SOLVING
Thinking Skills
Solve.
Find a number between 15 and 30 such that the reverse
of its digits is 9 more than the number itself.
When you reverse the
digits of 37, you get 73!
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1.
The number is
.
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Name:
2.
Date:
Each of the different shapes below has a number value.
The shapes in every row and column add up to the
numbers shown.
Can you find the value of each shape?
20
27
=
22
22
=
=
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Name:
3.
Date:
The picture shows some letters that are arranged in a
pattern.
Use the key to find the missing letter.
Key:
A=5
B=6
C=7
D=8
E=9
F = 10
G = 11
H = 12
I = 13
J = 14
K = 15
L = 16
M = 17
N = 18
O = 19
P = 20
Q = 21
R = 22
S = 23
T = 24
?
G
U = 25
V = 26
W = 27
X = 28
Y = 29
Z = 30
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B
S
The missing letter is
P
.
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Date:
PROBLEM SOLVING
Strategies
Solve using number lines.
Show your work.
Valerie has 14 goldfish in her fish tank.
She has 8 more guppies than goldfish.
She kept some mollies in another tank.
The number of mollies is 3 less than the number
of guppies.
How many mollies does Valerie have?
Valerie has
5.
Four years ago, Patrick was 15 years older than Susan.
At that time, Susan was 8 years old.
How old is Patrick now?
Patrick is
24
mollies.
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4.
years old now.
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Date:
Look at the number patterns.
Solve.
6.
The numbers below are arranged in a pattern.
One number is incorrect.
Which number is incorrect?
What should be the correct number?
8,
9,
11,
14,
19,
23
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is the incorrect number.
The correct number should be
7.
.
Find the number that comes next in the pattern.
3,
6,
12,
The number is
21,
?
.
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PROBLEM SOLVING
Exploration
Solve.
Show your work.
Daniel is 36 years old.
Olivia is 10 years younger than Daniel.
Simon is older than Olivia but younger than Daniel.
How old can Simon be?
,
Simon can be
,
or
26
,
,
,
,
,
,
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8.
years old.
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9.
Date:
Monica has five number cards that make a pattern.
She shows three of the number cards to Louise.
Arrange the cards to make the pattern.
What can the two other number cards be?
There is more than one correct answer.
14
20
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26
The two other number cards can be
and
.
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Journal Writing
10.
23 25 28 32 34
Do the numbers form a pattern?
Tell your friend why.
11.
20 24 28 32 36
Do the numbers form a pattern?
Tell your friend why.
Correct the mistakes.
Write the correct sentences.
12.
5 more than 19 is 14.
13.
10 less than 22 is 32.
28
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Solve and tell why.
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