Mathematics 2
2 – February 2011
Classwork #13
Exercise 1.
Easy
Difficult
Interesting
Boring
A. Hundreds and tens.
ten
ten
hundred
ten
ten
2h4t0u=
hundred
= 2 h 40 u = 24 t 0 u = 240
2 m 4 dm 0 cm = 2 m 40 cm = 24 dm 0 cm = 240 cm
B. Write and read three-digit numbers. Make their graphic models like in the sample.
4 h 6 t = 4 h 6 t 0 u = 4 h 60 u = 460 =
3h5t=
☐h☐t☐u=
= _____________________________
1h4t=
☐h☐t☐u=
= _____________________________
How many hundreds and tens in these numbers? How many tens? Which distances
correspond to these numbers?
C. What is the difference between 250 and 25? Draw the graphic models of these
numbers.
250 = _____________________________
25 = ______________________________
D. Write the appropriate numbers into the windows.
5h2t=
5 m 2 dm =
cm
52 t =
2h8t=
2 m 8 dm =
cm
28 t =
9h9t=
9 m 9 dm =
cm
99 t =
7h4t=
7 m 4 dm =
cm
74 t =
E. Solve the problem. A pine tree is 32 m tall. A birch tree is 14 m lower than the pine.
An oak is 3 m taller than the birch tree. How tall is the oak?
F. Hundreds, tens, and units. Fill in the table.
Hundreds
Tens
Units
Number
2
9
4
294
G. Read the numbers: 568, 452, 904, 780, 82, 375, 111, 203. How many hundreds, tens
and units are in these numbers? Express these numbers in hundreds and units. Express
them in tens and units.
H. Write the numbers with digits:
two hundred ninety six
eighty six
three hundred two
forty six
six hundred twenty seven
five hundred forty eight
one hundred eighty
nine hundred sixty
I. Solve the problems:
a). The length of a new born baby-whale was 5 m 3 dm 2 cm. Once he grew up his
length has become 32 m 6 dm 7 cm. How much did he grow up?
b). One an ant ran 16 m 4 dm 5 cm towards home he had 9 m 1 dm 3 cm left to run.
How long was his total way home?
c). Natasha has sent 16 New Year post cards and 9 March 8th post cards. She has
received herself 12 New year cards and 10 March 8th cards. How many more post cards
has Natasha sent than received?
Sent
?
Received
J. Calculate:
74 - 69
16 – 8
Exercise 2.
Easy
7+6
Difficult
48 + 37
Interesting
50 -29
Boring
Lisa's bag fits into Ann's bag. Ann's bag fits into Clara's bag. Whose bag is the biggest?
Man's body is colder than pigeon's body but warmer than elephant's body. Whose body
is the coldest?
How can three boys cross a river in a small boat that fits only two boys?
Two travelers that did not know how to swim came to a river bank. The was a small boat
there which could fit only one person. Nevertheless, both travelers have managed to
cross the river and continue their journey. How could that happen?
One man always tells lies. How will he answer the following question: “Do you have
one nose or two?”
Exercise 3.
Easy
Difficult
Interesting
Boring
Candylandia
Marshmallowlandia
Chocolandia
Wafflandia
M
1
M
Ca
2
M
3
Ca
Ca
W
Ch
W
W
Ca
Ch
Ch
4
Ch
W
M
Exercise 4.
Easy
Difficult
Interesting
Boring
Exercise 5.
Easy
Difficult
Interesting
Boring
3 point problems from the international Math Kangaroo competition.
1. A kangaroo is adding two hundred hundreds and one. Help him to find the right
answer.
A. 201
B. 1201
C. 2001
D. 20001
E. 200001
2. The drawing shows figures from 1 to 4 together with their mirror images. What
should be the next image?
3. Little Joseph has 7 sticks. He broke one of them in halves. How many sticks does he
have now?
A. 5
B. 6
C. 7
D. 8
E. 9
4. Katia wrote the sentence “I enjoy garden work” counted letters in each word,
multiplied the numbers and obtained:
A. 180
B. 120
C. 240
D. 30
E. 60
5. Sarah and Ruben both celebrate their birthdays on March 16th. Ruben was born when
Sarah was 3 years old. How old will he be when Sarah will be twice older than him?
A. 1
B. 2
C. 3
D. 4
E. 10
6. Which shapes are absent from the drawing?
A. rectangles
B. triangles
C. squares
D. circles
E. All are present
7. 19 girls and 12 boys are playing in the yard. How many kids need to join them so that
altogether they would be able to form 6 equal teams.
A. 1
B. 2
C. 3
D. 4
E. 5