4th Grade Math Practice Online

4th GRADE MATH PRACTICE ONLINE

Problem 1 :

How many three digit numbers are there ?

(A) 800 (B) 850 (C) 900

Solution :

Available digits are

0, 1, 2, 3, 4, 5, 6, 7, 8, 9

Number of three digit numbers

= 10⋅10⋅10

= 900

So, the number of three digit numbers are 900.

Problem 2 :

What is the roman numeral for 1000 ?

(A L (B) M (C) C

Solution :

Roman numeral of 1000 is M.

Problem 3 :

Which of the following numbers are divisible 9?

(A) 4268 (B) 3447 (C) 1342

Solution :

Sum of digits in (A) :

4268 ==> 4 + 2 + 6 + 8 ==> 20 (Not divisible by 9)

Sum of digits in (B) :

3447 ==> 3 + 4 + 4 + 7 ==> 18 (Divisible by 9)

Sum of digits in (C) :

1342 ==> 1 + 3 + 4 + 2 ==> 10 (Not divisible by 9)

So, 3447 is divisible by 9.

Problem 4 :

Write 800 in exponential form.

(A) 3⁵ x 2²(B) 2⁵ x 5²(C) 5⁵ x 3²

Solution :

800 = 2 ⋅ 2 ⋅ 2 ⋅ 2 ⋅ 2 ⋅ 5 ⋅ 5

= 2⁵⋅ 5²

Exponential form of 800 is 2⁵⋅ 5².

Problem 5 :

Two composite numbers which have no common factors are called mutually __________________.

(A) Prime (B) Composite (C) None of these

Solution :

Two composite numbers which have no common factors are called mutually prime.

Problem 6 :

A milk man had 15 liters of milk in a vessel and 20 liters of milk in another vessel. Find the maximum capacity of a measuring jar which the milkman uses to measure milk from either vessel an exact number of times.

Solution :

To find the maximum capacity of a measuring jar which the milkman uses to measure milk from either vessel an exact number of times, we find highest common factor of 15 an d 20.

15 = 5 ⋅ 3

20 = 2 ⋅ 2 ⋅ 5

Highest common factor is 5.

So the answer is 5 liters.

Problem 7 :

Find the L.C.M of 48, 56, 72 and 108.

(A) 3024 (B) 3115 (C) 1248

Solution :