Operations with Integers | FIO

Question 22

Given that (548)×972=532656(-548) \times 972 = -532656, write the values of:

(a) (547)×972(-547) \times 972

(b) (548)×971(-548) \times 971

(c) (547)×971(-547) \times 971

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Solution

We can use the distributive property of multiplication to solve these problems.

Step 1 — Calculate (547)×972(-547) \times 972

We are given the product of -548 and 972. We need to find the product of -547 and 972. Notice that -547 is one more than -548. So, we can write -547 as (548+1)(-548 + 1). Now, we multiply this by 972. We use the distributive property of multiplication. This means we multiply each part inside the bracket by 972. Then, we add the results together.

(547)×972=(548+1)×972(-547) \times 972 = (-548 + 1) \times 972

=(548)×972+1×972= (-548) \times 972 + 1 \times 972

=532656+972= -532656 + 972

=531684= -531684

531684\boxed{-531684}

Step 2 — Calculate (548)×971(-548) \times 971

We need to find the product of -548 and 971. Notice that 971 is one less than 972. So, we can write 971 as (9721)(972 - 1). Now, we multiply -548 by this expression. We use the distributive property again. This means we multiply -548 by each part inside the bracket. Then, we subtract the second result from the first.

(548)×971=(548)×(9721)(-548) \times 971 = (-548) \times (972 - 1)

=(548)×972(548)×1= (-548) \times 972 - (-548) \times 1

=532656(548)= -532656 - (-548)

=532656+548= -532656 + 548

=532108= -532108

532108\boxed{-532108}

Step 3 — Calculate (547)×971(-547) \times 971

We need to find the product of -547 and 971. We know that -547 can be written as (548+1)(-548 + 1). We also know that 971 can be written as (9721)(972 - 1). So, we will multiply these two new expressions. We use the distributive property twice. We multiply each term from the first bracket by each term from the second bracket.

(547)×971=(548+1)×(9721)(-547) \times 971 = (-548 + 1) \times (972 - 1)

=(548)×972(548)×1+1×9721×1= (-548) \times 972 - (-548) \times 1 + 1 \times 972 - 1 \times 1

=532656(548)+9721= -532656 - (-548) + 972 - 1

=532656+548+9721= -532656 + 548 + 972 - 1

=532656+15201= -532656 + 1520 - 1

=5311361= -531136 - 1

=531137= -531137

531137\boxed{-531137}

Answer

(a) (547)×972=531684(-547) \times 972 = \mathbf{-531684} (b) (548)×971=532108(-548) \times 971 = \mathbf{-532108} (c) (547)×971=531137(-547) \times 971 = \mathbf{-531137}

More questions in FIO

Q1

Let us try to find a few more pairs of numbers from their sums and differences:

(a) Sum = 27, Difference = 9

(b) Sum = 4, Difference = 12

(c) Sum = 0, Difference = 10

(d) Sum = 0, Difference = -10

(e) Sum = -7, Difference = -1

(f) Sum = -7, Difference = -13

Q2

Using the token interpretation, find the values of:

(a) 3×(2)3 \times (-2)

(b) (5)×(2)(-5) \times (-2)

(c) (4)×(1)(-4) \times (-1)

(d) (7)×3(-7) \times 3

Q3

If 123×456=56088123 \times 456 = 56088, without calculating, find the value of:

(a) (123)×456(-123) \times 456

(b) (123)×(456)(-123) \times (-456)

(c) (123)×(456)(123) \times (-456)

Q4

Try to frame a simple rule to multiply two integers.

Consider the numbers represented by the following tokens in the diagram:

Q5

Find the following products.

(a) 4×(3)4 \times (-3)

(b) (6)×(3)(-6) \times (-3)

(c) (5)×(1)(-5) \times (-1)

(d) (8)×4(-8) \times 4

(e) (9)×10(-9) \times 10

(f) 10×(17)10 \times (-17)

Q6

Find the values of:

(a) 14×(15)14 \times (-15)

(b) 16×(5)-16 \times (-5)

(c) 36÷(18)36 \div (-18)

(d) (46)÷(23)(-46) \div (-23)

Q7

A freezing process requires that the room temperature be lowered from 32C32^\circ\text{C} at the rate of 5C5^\circ\text{C} every hour. What will be the room temperature 10 hours after the process begins?

Q8

A cement company earns a profit of ₹8 per bag of white cement sold and a loss of ₹5 per bag of grey cement sold. [Represent the profit/loss as integers.]

(a) The company sells 3,000 bags of white cement and 5,000 bags of grey cement in a month. What is its profit or loss? (b) If the number of bags of grey cement sold is 6,400 bags, what is the number of bags of white cement the company must sell to have neither profit nor loss?

Q9

Replace the blank with an integer to make a true statement.

(a) (3)×=27(-3) \times \underline{\quad\quad} = 27

(b) 5×=(35)5 \times \underline{\quad\quad} = (-35)

(c) ×(8)=(56)\underline{\quad\quad} \times (-8) = (-56)

(d) ×(12)=132\underline{\quad\quad} \times (-12) = 132

(e) ÷(8)=7\underline{\quad\quad} \div (-8) = 7

(f) ÷12=11\underline{\quad\quad} \div 12 = -11

Q10

Find the values of the following expressions: (a) (5)×(18+(3))(-5) \times (18 + (-3)) (b) (7)×4×(1)(-7) \times 4 \times (-1) (c) (2)×(1)×(5)×(3)(-2) \times (-1) \times (-5) \times (-3)

Q11

Find the values of the following expressions:

(a) (27)÷9(-27) \div 9

(b) 84÷(4)84 \div (-4)

(c) (56)÷(2)(-56) \div (-2)

Q12

Find the integer whose product with (1)(-1) is:

(a) 27

(b) -31

(c) -1

(d) 1

(e) 0

Q13

If 4756+148+28+5=447 - 56 + 14 - 8 + 2 - 8 + 5 = -4, then find the value of 47+5614+82+85-47 + 56 - 14 + 8 - 2 + 8 - 5 without calculating the full expression.

Q14

Do you remember the Collatz Conjecture from last year? Try a modified version with integers. The rule is — start with any number; if the number is even, take half of it; if the number is odd, multiply it by 3-3 and add 1; repeat. An example sequence is shown below.

Try this with different starting numbers: (21)(-21), (6)(-6), and so on. Describe the patterns you observe.

Q15

In a test, (+4) marks are given for every correct answer and (-2) marks are given for every incorrect answer.

(a) Anita answered all the questions in the test. She scored 40 marks even though 15 of her answers were correct. How many of her answers were incorrect? How many questions are in the test?

(b) Anil scored (-10) marks even though he had 5 correct answers. How many of his answers were incorrect? Did he leave any questions unanswered?

Q16

Pick the pattern — find the operations done by the machine shown below.

Q17

Imagine you're in a place where the temperature drops by 5°C each hour. If the temperature is currently at 8°C, write an expression which denotes the temperature after 4 hours.

Q18

Find 3 consecutive numbers with a product of (a) -6, (b) 120.

Q19

An alien society uses a peculiar currency called 'pibs' with just two denominations of coins — a+13 pibs coin and a -9 pibs coin. You have several of these coins. Is it possible to purchase an item that costs +85 pibs?

Q20

Find the values of:

(a) (32×(18))÷((36))(32 \times (-18)) \div ((-36))

(b) (32)÷((36)×(18))(32) \div ((-36) \times (-18))

(c) (25×(12))÷((45)×(27))(25 \times (-12)) \div ((45) \times (-27))

(d) (280×(7))÷((8)×(35))(280 \times (-7)) \div ((-8) \times (-35))

Q21

Arrange the expressions given below in increasing order:

(a) (348)+(1064)(-348) + (-1064)

(b) (348)(1064)(-348) - (-1064)

(c) 348(1064)348 - (-1064)

(d) (348)×(1064)(-348) \times (-1064)

(e) 348×(1064)348 \times (-1064)

(f) 348×964348 \times 964

Q22

Given that (548)×972=532656(-548) \times 972 = -532656, write the values of:

(a) (547)×972(-547) \times 972

(b) (548)×971(-548) \times 971

(c) (547)×971(-547) \times 971

Q23

Given that 207×(33+7)=5382207 \times (-33 + 7) = -5382, write the value of 207×(337)=___?-207 \times (33 - 7) =\_\_\_?

Q24

Use the numbers 3,2,5,63, -2, 5, -6 exactly once and the operations '+', '-', and 'x' exactly once and brackets as necessary to write an expression such that —

(a) the result is the maximum possible

(b) the result is the minimum possible

Q25

Fill in the blanks in at least 5 different ways with integers:

(a) +×=36\square + \square \times \square = -36

(b) ()×=12(\square - \square) \times \square = 12

(c) (())=1(\square - (\square - \square)) = -1

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