Download UNIT 1: DIVISIBILITY. INTEGERS NUMBERS. REVIEW 2ºESO

UNIT 1: DIVISIBILITY. INTEGERS NUMBERS. REVIEW
2ºESO
1. Answer the next questions and give your reasons.
a.
Is 45 a multiple of 405?
b.
Is 18 a factor of 9?
c.
Is 475 a multiple of 25?
d.
Is 930 a factor of both 5 and 3?
2. Indicate if the followings sentences are true or false and give reasons. If they are false, give an example:
a.
The multiples of a given number are equal to or bigger than it.
b.
All the prime numbers are odd numbers.
c.
An Odd number cannot be a composite numbers.
d.
If a number a is multiple of other number b, then b is factor of a.
3. Write a number with 4 digits, divisible by both of the followings numbers:
a.
2 and 3
c.
3 and 25
b.
2 and 5
d.
4 and 100
4. If a number is divisible by 4, it is divisible by 2 also? Give your reasons.
If a number is divisible by 3, it is divisible by 9 also? Give your reasons.
5. Find the HCF and LCM of 16, 24 and 28.
6. Leonard wants to cut identical squares as big as he can from a piece of paper 168 mm by 196mm. What is the length of
each square?
7. Eddie owns three motorcycles. He cleans the Harley once every 8 days, the Honda once every 10 days and the Kawasaki
once every 15 days. Today he cleaned all three motorcycles. When will he next clean all three motorcycles on the same
day?
8. A classroom has an area of 144 m2.
a.
b.
Write the prime factor decomposition of 144.
Find the dimensions of the classroom if it is
i. Square
ii. 16 m long
iii. 18m long
9. Extract the common factor from these expressions:
a.
-4 · 5 – 4 · 7 =
b. 25 + 30 =
b.
-15 + 9 =
10. Work out the following combined operations:
a. -20 : 4 : (-5)+8·3=
b. 5 · ( -3 + 6 · 2 ) - 24 : (-3) =
c. 9 · 2 – [6 – 4 · (-3)] =
d. 9 : ( -2 -1 ) - [5 · ( 3 – 1 ) -7 · 4] =
e. - 3 · [ 9 + 6 : ( -2 )] + 5 · 9 =
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