Page 40 - ICSE Math 6

(d) The product of two whole numbers is 1 only if both of them are 1.
(e) Division by zero is meaningless, hence it is not defined.
2. Fill in the blanks.

(a) On multiplying any whole number a by 1 we get back ____________, hence 1 is called the
____________ of the whole numbers.

(b) Since 8 – 2 ≠ 2 – 8, hence ___________ property is not true for subtraction of whole numbers.
(c) According to the division algorithm, dividend = quotient × ____________ + remainder.
(d) The _____________ property of addition of whole numbers states that on adding any two
whole numbers the result is again a ____________ number.
(e) Since the whole numbers satisfy ____________ property of multiplication over addition, we
can say that 5 × (3 + _______) = 5 × 3 + 5 × 2.
(f) When zero is divided by any natural number, the answer is always ____________.

PRACTICE TIME

1. Write the predecessor of 1,02,999.
2. Write the successor of 76,85,949.
3. Find the sum of 2 and 7 using a number line.
4. Find the product of 3 and 6 using a number line.
5. Simplify 256 × 55 + 45 × 256 using properties of whole numbers.

6. Find the value of 1,738 × 125 – 1,738 × 25.
7. Simplify (256 ÷ 16) ÷ 4.
8. Find the least 5-digit number exactly divisible by 33.
9. By studying the pattern given below, evaluate the following.
2 × 3 3 × 4 4 × 5
Pattern: 1 + 2 = 1 + 2 + 3 = 1 + 2 + 3 + 4 =
2 2 2
(a) 1 + 2 + 3 + .... + 100 (b) 30 + 31 + 32 + .... + 50
10. A bus driver filled the bus tank with 33 L of diesel. Two days later he filled the tank with 17 L
of diesel. If the diesel costs ` 62 per litre, how much did he spend in all on diesel?

11. A cloth shop sold 65 white, 70 black and 35 blue shirts in May. It sold 70 white and 35 black
shirts in June. If it sold the same number of shirts each month, how many shirts other than black
and white in colour did it sell in June? If each shirt was sold for ` 700, how much did the shop
make each month by selling shirts?
(Hint: Use properties of whole numbers.)

THINK SMART

1. What is the difference between the successor and predecessor of a number?
2. Add the predecessor of 4 and successor of 5 on the number line.

3. What answer will you get if you subtract the sum of all natural numbers from the sum of all
whole numbers?
4. What are the next two numbers in the series given below?
2, 6, 12, 20, ___, ___

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