Q1: Find the values of the following expressions by writing the terms in each case.
(a) 35 - 8 + 9
Ans: Terms: 35, -8, 9.
Expression: 35 + (-8) + 9
= 27 + 9
= 36.
(b) 50 - 3 × 7 + 13
Ans: Terms: 50, -3 × 7, 13.
Expression: 50 + (-21) + 13
= 50 - 21 + 13
= 42.
(c) 60 - 15 + 5 + 10
Ans: Terms: 60, -15, 5, 10.
Expression: 60 + (-15) + 5 + 10
= 45 + 5 + 10
= 60.
Q2: Use ‘>’ or ‘<’ or ‘=’ in each of the following expressions to compare them. Can you do it without complicated calculations? Explain your thinking in each case.
(a) 322 + 215 ____ 324 + 213
Ans: Left side: 322 + 215 = 537
Right side: 324 + 213 = 537
322 + 215 = 324 + 213 (They are equal)
(b) 571 + 432 ____ 570 + 434
Ans: Left side: 571 + 432 = 1003
Right side: 570 + 434 = 1004571 + 432 < 570 + 434
(c) 418 – 234 ____ 414 – 238
Ans: Left side: 418 - 234 = 184
Right side: 414 - 238 = 176
418 - 234 > 414 - 238
Q3: Compare and answer if LHS = RHS .
(a) 4 × (5 + 8) = 4 × 5 + 4 × 8
Ans: This is already correct.
LHS = 4 × (5 + 8) = 4 × 13 = 52
RHS = 4 × 5 + 4 × 8 = 20 + 32 = 52
(b) 6 × (3 + 7) = 6 × 3 + 7
Ans: This is incorrect.
LHS = 6 × (3 + 7) = 6 × 10 = 60
RHS = 6 × 3 + 7 = 18 + 7 = 25
Q4: Fill in the blanks to make the expressions equal on both sides of the = sign:
(a) 15 + 6 = _____ + 8
Ans: 15 + 6 = 21,
so 13 + 8 = 21.
The blank is 13.
(b) 30 + _____ = 5 × 8
Ans: 5 × 8 = 40,
so 30 + 10 = 40.
The blank is 10.
(c) 9 × _____ = 72 ÷ 3
Ans:
72 ÷ 3 = 24,
so 9 × 4 = 24.
The blank is 4.
(d) 50 - _____ = 40
Ans: 50 - 10 = 40.
The blank is 10.
Q5: Compare the following pairs of expressions using '<', '>', or '='
(a) 72 × 34 - 15 ___ 72 × 30 - 15
Ans: LHS = 72 × 34 - 15
Let us first solve 72 x 34 = 72 × (30 + 4)
= 72 × 30 + 72 × 4.
So, 72 × 34 - 15 = 72 × 30 + 72 × 4 - 15, and
RHS = 72 × 30 - 15
So, 72 × 34 - 15 > 72 × 30 - 15
(b) 63 - 9 + 5 ___ 63 - 9 + 5
Ans: Same expression.
So, 63 - 9 + 5 = 63 - 9 + 5.
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$1. What are large numbers and how are they used in everyday life? | ![]() |
$2. How do we represent large numbers in a simplified way? | ![]() |
$3. Why is it important to learn about large numbers in mathematics? | ![]() |
$4. Can you give examples of large numbers found in nature? | ![]() |
$5. How do we compare large numbers effectively? | ![]() |