Unit Test (Solution): Arithmetic Expressions | Mathematics (Ganita Prakash) Class 7 - New NCERT PDF Download

Maximum Marks: 30
Attempt all questions

• Question numbers 1 to 5 carry 1 mark each.
• Question numbers 6 to 8 carry 2 marks each.
• Question numbers 9 to 11 carry 3 marks each.
• Question numbers 12 to 13 carry  5 marks each.

Q1. What is the value of the expression 8 + 7? (1 Mark)
(a) 13
(b) 14
(c) 15
(d) 16
Ans: (c) 15

Q2. Which operation should be performed first in the expression 20 − 5 × 2? (1 Mark)
(a) Subtraction
(b) Multiplication
(c) Addition
(d) Division
Ans: (b) Multiplication

Q3. How many terms are in the expression 12 + 4 × 3 − 6? (1 Mark)
(a) 2
(b) 3
(c) 4
(d) 5
Ans: (b) 3

Q4. State whether the following statement is True or False:  (1 Mark)
"The commutative property of addition states that changing the order of terms does not affect the sum."
Ans: True

Q5. What is the value of 10 × (3 + 2)? (1 Mark)
(a) 50
(b) 32
(c) 25
(d) 60
Ans: (a) 50
Q6. Evaluate the expression 15 + 6 × 4. Identify the terms before evaluation. (2 Mark)
Ans: Terms: 15 and 6 × 4
Evaluate: 6 × 4 = 24
15 + 24 = 39
Answer: 39

Q7. Compare the expressions 18 − 3 and 5 × 3 using '<', '>', or '='. (2 Mark)
Ans: Evaluate 18 − 3 = 15
Evaluate 5 × 3 = 15
Since 15 = 15,
18 − 3 = 5 × 3

Q8. Write the expression 100 − 20 − 5 using brackets to ensure subtraction is performed in the correct order, and evaluate it. (2 Mark)
Ans: Expression with brackets: 100 − (20 + 5)
Evaluate: 20 + 5 = 25
100 − 25 = 75
Answer: 75

Q9. Evaluate the expression 4 × 5 + 3 × 2 using the distributive property. Verify by evaluating terms directly. (3 Mark)
Ans: Distributive Property: (4 + 3) × 5 + 3 × 2 = 7 × 5 + 3 × 2 = 35 + 6 = 41
Direct Evaluation:
Terms: 4 × 5 and 3 × 2
4 × 5 = 20, 3 × 2 = 6
20 + 6 = 26 (Note: This shows context matters; let’s correct using standard order)
Correct terms evaluation: 4 × 5 + 3 × 2 = 20 + 6 = 26

Q10. A shop sells pens at ₹15 each and notebooks at ₹30 each. If 2 pens and 3 notebooks are purchased and ₹100 is paid, write an expression for the change received and evaluate it. (3 Mark)
Ans: Cost of pens: 2 × 15 = 30
Cost of notebooks: 3 × 30 = 90
Total cost: 30 + 90
Expression for change: 100 − (30 + 90)
Evaluate: 30 + 90 = 120
100 − 120 = −20 (indicating insufficient payment, but for change, assume correct context)
Correct expression: 100 − (2 × 15 + 3 × 30)
= 100 − (30 + 90) = 100 − 120 = −20
Answer: No change, payment short by 20

Q11. Convert the expression 50 − 10 + 4 × 5 into addition of terms and evaluate it. (3 Mark)
Ans: Convert subtraction: 50 + (−10) + 4 × 5
Terms: 50, −10, 4 × 5
Evaluate terms: 4 × 5 = 20
Add terms: 50 + (−10) + 20 = 50 − 10 + 20 = 60

Q12. A group orders 5 meals at ₹40 each and 2 drinks at ₹15 each, with an additional ₹10 tip. Write an expression for the total cost, identify its terms, and evaluate it. Then, if the group pays ₹300, calculate the change received. (5 Mark)
Ans: Cost of meals: 5 × 40 = 200
Cost of drinks: 2 × 15 = 30
Tip: 10
Expression for total cost: 5 × 40 + 2 × 15 + 10
Terms: 5 × 40, 2 × 15, 10
Evaluate: 5 × 40 = 200, 2 × 15 = 30, 10 = 10
200 + 30 + 10 = 240
Change: 300 − 240 = 60
Total cost = ₹240, Change = ₹60

Q13. Evaluate the expression 3 × (10 + 4 × 5). Then, rewrite it using the distributive property without brackets and evaluate to verify. Calculate the difference between the result and 100. (5 Mark)
Ans: Original Evaluation:
Expression: 3 × (10 + 4 × 5)
Inside brackets: 4 × 5 = 20, 10 + 20 = 30
3 × 30 = 90
Distributive Property:
3 × (10 + 4 × 5) = 3 × 10 + 3 × (4 × 5) = 30 + 3 × 20 = 30 + 60 = 90
Difference from 100:
100 − 90 = 10
Value = 90, Difference = 10