Page 314 - Start Up Mathematics_8 (Non CCE)

solve Mentally
True or False
1. If a number is divisible by 2, then it must be divisible by 4.
2. The least value of (x + y) if 4xy7 is exactly divisible by 3 is 1.
3. The sum of a 2-digit number and its reversing number is always a multiple of 9.
4. If x5y4z is exactly divisible by 9, then the least value of x + y + z is 6.
5. If a number exactly divides the sum of two numbers, it must exactly divide the numbers separately.

Answer in One Word or a Line
1. For a 3-digit number abc, what will be the quotient if abc – cba is divided by 11?
2. When is a 3-digit number abc divisible by 6?
3. Explain whether 95 is divisible by 3 or not.
4. Which of these—675, 931, 429, 283 and 720 is/are divisible by 9?

let’s evaluate
1. If 61x52 is a multiple of 9, where x is a digit, then what is the value of x?
2. If 7y4 is a multiple of 4, where y is a digit, then what is the value of y?
3. Find X in the addition.
3 8 X
+ 4 X 2
8 3 7

Thinking Skills

5C
1. In the following problem, replace the letters of English alphabet by
4AB
digits (two or more letters may have the same value) to complete the 9 –DE
procedure of division. 3F
–GH
0

2. In the 4 × 5 array given alongside, place the numbers from 1 to 20 (without
repetition) so that a sequence (chain of numbers) is obtained from 1 to 20. You 7 10
can move to the adjacent cell to the left, right, up or down but not diagonally.
The positions of the numbers that already exist are fixed.
2 17

3. Fill in the circle with the correct digits.

2 5
¥ 4 3 9

4 5 X
1 0 6 0 X X

4 9 8

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