Maharashtra Board Class 4 Maths Part Two Chapter 13 Multiplication PDF Download

Multiplication: Part 2

Seven students of Std IV received a scholarship of ₹ 315 each. What was the total amount of the scholarship received by the students?

We can find the total scholarship amount by multiplying 315 by 7. Let us multiply using the lattice method, keeping in mind that 315 = 300 + 10 + 5.

The total scholarship amount received by the students is ₹ 2205.

Nandu: Tai, last year we learned a different method of multiplying two-digit numbers vertically. Can we use that method here?

Tai: Yes. Let us find 315 × 7 using that method.

First, we multiply 5 units by 7 units. The product is 35 units. 35 units = 3 tens + 5 units. Write these 3T in the carried over tens place.

Now, 1 T × 7 = 7 T. To this, we add the 3 carried over tens. The sum is 10 tens. 10 tens are equal to 1 H + 0 T. Write 0 in the tens place and 1H above the hundreds place.

3 H × 7 = 21 H and 1 H carried over makes 22 H. 22 H = 2 Th + 2 H. Put the 2 Th in the thousands place. Now the digits in the Th, H, T, U places are 2, 2, 0, 5 in that order. The answer is 2205.

Salma: We had to make a thousands place to write this multiplication.

Teacher's Note

In real life, when shopkeepers in India buy things in bulk, they use multiplication like this to count total items. For example, if a shop buys 7 boxes with 315 pencils in each box, they multiply to find how many pencils they have in all.

Exam Trick

Remember: When you multiply and get a number like 35, it means 3 tens and 5 units. Write the 5 in the units place and carry over the 3 to the tens place. This helps you get the right answer.

Points to Remember

Multiplication can be done using the lattice method or the vertical method.

When you multiply units by a number, you may get tens. Always carry over the tens to the next place.

When you multiply tens by a number, remember to add the carried over tens to your answer.

The final answer should have all digits in the correct place value.

Exercise

Multiply the following.

Teacher's Note

Practice these exercises like you practice drawing. The more you do them, the faster and better you become at multiplication.

Exam Trick

In the exam, first write down the carried over number in small writing above the place value column. This stops you from making mistakes.

Points to Remember

Always multiply the units first.

Then multiply the tens and add any carried over number.

Write small numbers above the columns to show what you carried over.

Amit: We can also multiply two two-digit numbers using this vertical method!

Tai: Yes, you can. Let me show you an example using both methods.

38 × 24

Sonu: I understood that 38 × 4 = 152. But, I didn't understand how we got the 0 when multiplying by 2 tens.

Tai: That's simple. Multiplying 8 units by 2 tens, we get 16 tens. 16 T = 1 H + 6 T. 6 tens stay in the tens place and 1 hundred is carried over to the next place. Multiplying any number with a ten, the product is always in whole tens. Therefore, we write a 0 in the units place.

Nanду: Tai, I have realized something after studying both methods. In the vertical arrangement, multiplying 38 by 4 units gives us 152; in the lattice method, multiplying 30 and 8 by 4 gives us 120 and 32. The sum of 120 and 32 is also 152!

Tai: Excellent! Did you find out anything else?

Sonu: In the lattice method, we carried out four small multiplications and added them. In the vertical method, we solved two slightly bigger multiplications and added the products. That took less time.

Exercise

1. Multiply.

2. Multiply.

(1) 223 × 3 (2) 127 × 8 (3) 85 × 17 (4) 31 × 26 (5) 26 × 31

3. Solve the problems given below.

(1) Find out the total cost of 3 shirts costing ₹ 495 each.

(2) Aminabai bought 6 crates of apples, each costing ₹ 325. How much did she pay altogether?

(3) In a mango grove, there are 45 rows, with 32 trees in each row. How many mango trees are there in the grove?

(4) If one book costs ₹ 80, how much do 25 such books cost?

(5) Seema bought 2 dresses for ₹ 695 each. How much did she pay in all?

(6) If one sack of wheat weighs 53 kilograms, how much do 19 such sacks weigh?

(7) A car travels a distance of 16 km on one litre of petrol. How many kilometres will it travel on 35 litres?

(8) If 365 trees can be planted on 1 hectare of an orchard, how many trees can be planted on 8 hectares?

Teacher's Note

These word problems show real Indian life. For example, buying clothes, fruits, or books uses multiplication every day.

Exam Trick

Read the problem two times. Find which two numbers you need to multiply. Then do the multiplication step by step.

Points to Remember

Word problems tell you a story about something that happens in real life.

You need to find which numbers to multiply by reading the problem carefully.

Always write the answer with the correct unit like rupees, kilograms, or kilometres.

Sonu: We can use the vertical arrangement to multiply three-digit numbers by two-digit numbers, can't we?

Tai: Of course, we can. In fact, we can use this method to multiply any number by any number no matter how many digits they have. Let me show you one example. Watch carefully and tell me whether or not you understand.

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