Learn Class 8 Math - Playing with Numbers

What is the General Form of Numbers?

For PQ, if the general form is needed, it will look like this:

pq=10p+q

Games with Numbers

Reversing the Digits – Two-Digit Number

Step 1: Let us select any two-digit number ab, which may be written as (10a + b).

Step 2: Its opposite two-digit number can be ba, which may be written as (10b + a).

Step 3: The sum of each of the numbers is ab + ba,

Step 4: By dividing the number by 11, we get eleven (a + b)/11 = (a + b).

Reversing the Digits – Three Digit Number

Step 1: Let's pick any 3 digit quantity ABC, which may be written as (100a + 10b + c).

Step 2: Its opposite quantity can be CBA, which may be written as (100c + 10b + a).

Step 3: By subtracting each of the numbers, i.e. ABC - CBA

Step 4: By dividing the quantity via 99 we get 99 (a-c)/9 = (a-c).

Forming Three-digit Numbers with three digits.

Step 1: Let us take any 3 digit quantity ABC, which may be written as (100a +10b + c).

Step 2: Rearrange the quantity in this type of manner that is bureaucracy specific numbers.

Step 3:By including all of the 3 numbers

Step 4:By dividing the quantity by 37, we usually get the rest zero.

Playing with Numbers Sample Questions for Class 8

Question 1

is equal to :
A. 1
B. 2
C. 689
D. 1023

Question 2

(51 + 52 + 53 + ..... + 100) is equal to :
A. 2525
B. 2975
C. 3225
D. 3775

Question 3

is equal to:
A. 2
B. 4
C. 295
D. 643

Question 4

If x is an even number, then x4n, where n is a positive integer, will always have :
A. zero in the unit's place
B. 6 in the unit's place
C. either 0 or 6 in the unit's place
D. None of these

Question 5

2 – (?)2 = 4398 – 3066
A. 16
B. 28
C. 36
D. 42