Mental Maths Questions and Answers: Fractions and decimals | Mental Math for Class 7 PDF Download

Q1: Evaluate:
Ans:

Q2: Find the sum of: 
Ans: 

Q3: Simplify:
Ans: 

Q4: What should be subtracted from 12 to get 17/2 ?
Ans: 

Q5: What should be added to  to get 12?
Ans: 

Q6: Find the value of  of 7.
Ans: 

Q7: Simplify:
Ans: 1/4

Q8: Find 3/20 of 1 kg in grams.
Ans: 150 g

Q9: Find 7/20  of a litre in ml.
Ans: 350 ml

Q10: Pooja plants 6 saplings in a row in her garden. The distance between two adjacent saplings is 3/5 m. Find the distance between the first and the last sapling.
Ans: 3 m

Q11: Rani ate 2/7 part of a cake while her brother Rahul ate 4/5 of the remaining. What part of the cake is left?
Ans: 1/7

Q12: What is the reciprocal of 3/7 of 2/5 ?
Ans: 

Q13: The length and breadth of a rectangle are  and 3 m respectively. Find its perimeter.
Ans: 

Q14: How many small pieces of length 3/4 m can be cut from a ribbon of length ?
Ans: 7 Pieces

Q15: If the cost of 20 pens is ₹356.80, then find the cost of one such pen.
Ans: ₹17.84

Q16: Simplify:
Ans: 18/31

Q17: Simplify: 0.011 x 0.39 ÷ 0.13
Ans: 0.033

Q18: Simplify:
Ans: 

Q19: Dinesh went from place A to place B and from there to place C. Ayub went from place A to place D and from there to place C. Who travelled more and by how much?
Ans: Ayub, 0.9 km

Q20: Find the value of: 1.07 x 65 + 1.07 x 26 + 1.07 x 9
Ans: 107

Q21: What fraction is represented by shaded portion?
Ans: 3/6

Q22: What is four fifth of half?
Ans: 2/5

Q23: Multiply the sum of 1 and  by the difference of 4 and
Ans: 

Q24: Convert 149/4 into a decimal.
Ans: 37.25

Q25: The cost of  of apples is ₹ 600. What is the cost of 1 kg of apples?
Ans: ₹96

Q26: What should be added to 385.70 to get 499.32?
Ans: 113.62

Q27: By how much 72.46 be decreased to get 29.73?
Ans: 42.73

Q28: What decimal is shown by A on a number line?
Ans: 0.05

Q29: If 2/3 of a number is 10, then what is 1.75 times of that number?
Ans: 26.25

Q30: Each side of a regular polygon is 1.2 cm in length. The perimeter of the polygon is 14.4 cm. How many sides does the polygon have?
Ans: 12 sides

Q31: Find the product: 6.001 x 0.001 x 9
Ans: 0.054009

Q32: Find the value of: 76 ÷ 0, .019
Ans: 4000

Q33: What is the sum of place values of 2 in 2364.028?
Ans: 2000.02

Q34: Find the area of a rectangle whose length is 6.5 m and breadth is 3.5m.
Ans: 22.75 sq. meter

Q35: Find the value of 325.67 ÷ 10000.
Ans: 0.032567

Q36: Convert into decimal:
Ans: 37.15

Q37: Arrange in descending order 14. 6,159,1.07, —1.295, 24.6
Ans: 159, 24.6, 14.6, 1.07, −1. 295

Q38: The side of a square field is 5.5 m, find the area of the square field.
Ans: 30.25 sq meter 

Q39: Find the area of a rectangle in sq. meter if its length and breadth are 16 cm and 12 cm respectively.
Ans: 0.0192 sq meter

Q40: Simplify:
Ans: 13/27

Q41: A plant is 1.17 cm high. It grows 1.1 times. What is its height now?
Ans: 1.287 cm

Q42: A grocer mixes 20.25 kg of green tea with 25.20 kg of ordinary tea and repacks all tea in 45 packets of equal weight. How much does each packet of tea weight?
Ans: 1.01 kg

Q43: A flask weighs 64.27 kg when empty and 150.35 kg when full of water. Find its weight when it is half full of water.
Ans: 107.31 kg

Q44: From the given number line, find (A + B)
Ans: −0.3

Q45: Evaluate: 1.564 - 0.500 + 3.001 - 2.500
Ans: 1.565

Q46: 4.5 kg of sweets are shared equally among 5 children. How many grams of sweets does each child get?
Ans: 900 gram

Q47: A book case is 2.38 m tall and the height of each shelf is 34 cm. How many shelves are there?
Ans: 7 shelves 

Q48: (i) Arrange the following in increasing order :

(ii) Arrange the following in decreasing order:
Ans: 

Q49: Find the perimeter of the given figure
Ans: 22 cm

Q50: What is the least positive fraction that must be added to  to make the result an integer?
Ans: 4/5

For detail explanation of solutions refer to the videos provided