S. K. Gupta Anubhuti Gangal Class 5 Math First Chapter Looking Back Exercise 3

 EXERCISE 3

(1) Write the simplest multiplication numeral for following:

(a) 5 + 5 + 5 + 5 + 5 + 5 = 5 × 6

(b) 0 + 0 + 0 + 0 = 0 × 4

(c) 137 + 137 + 137 + 137 = 137 × 4

(2) Multiply:

(a) 53 by 10, 100, 1000, 10,000

Ans: (i) 53 × 10 = 530

(ii) 53 × 100 = 5300

(iii) 53 × 1000 = 53000

(iv) 53 × 10000 = 530000

(b) 510 by 80

Ans: 40800

(c) 3900 by 50

Ans: 195000

(3) Find the product:

(a) 18 × 1 = 18

(b) 30 × 0 = 0

(c) 825 × 1 = 825

(d) 407 × 0 = 0

(4) Fill in the blanks:

(a) 879 × 1 = 879

(b) 0 × 1 = 0

(c) 58 × 729 = 729 × 58

(d) 59246 × 0 = 0

(5) Multiply:

(6) A machine, on an average, manufactures 3786 screws in a day. How many screws does it manufacture in one year?

Solution: Here, 1 year = 365 days

So, 3786 × 365 = 13,81,890.

Hence, 1381890 screws did it manufacture in one year.

(7) A factory produces 470 toy-cars a day. How many cars did it produce in the year 1988, if there are 86 holidays?

Solution: We know, there are 365 days in a year. But 1988 is a lip year so there are 366 days in year 1988. Here, given 86 holidays in that year.

Now, 470 × (366 – 86) = 470 × 278 = 130660.

So, the required number of toy is 130660, which is produced in year 1988.

(8) An aero plane, on an average, covers 7000 km in 12 hours. How much distance will it cover in 15 days?

Solution: Here, 15 days = 360 hours. We know, the aero plane covers 7000 km in 12 hours.

So, 7000 × (360 ÷ 12) = 7000 × 30 = 210000 km.

Hence, the required distance is 210000 km.

(9) A factory packs 144 ball pens in a carton. They have 395 cartons to be filled. They have already made 57,000 ball pens. Do they need to make more ball pens in order to fill all the cartons?

Solution: Here, 395 × 144 = 56880 pen to be needed.

Already made 57,000 pens.