Multiplication β€” 3-Digit Γ— 2-Digit

Mathematics

Class 5 | CBSE, NCERT & ICSE

Learning Objectives

Introduction β€” Multiplication in Daily Life

In Class 4, you learned to multiply 2-digit numbers by 2-digit numbers. Now in Class 5, we take it further β€” you will learn to multiply 3-digit numbers by 2-digit numbers and even begin working with 4-digit numbers!

Think about these real-life situations:

  • A school orders 48 boxes of notebooks, and each box has 125 notebooks. How many notebooks in total? (125 Γ— 48)
  • A train travels 345 km every day. How far does it travel in 28 days? (345 Γ— 28)
  • Arjun's father buys 36 bags of rice at β‚Ή750 per bag. What is the total cost? (750 Γ— 36)
  • A farmer plants 64 rows of mango saplings with 215 saplings in each row. How many saplings in all? (215 Γ— 64)

All of these need 3-digit Γ— 2-digit multiplication. Let us learn how to do it step by step!

Quick Revision β€” What You Already Know

Before we begin, let us quickly revise what multiplication means and some facts you already know:

What is Multiplication?

  • Multiplication is repeated addition. For example: 5 Γ— 3 = 5 + 5 + 5 = 15
  • The numbers being multiplied are called factors. The answer is called the product.
  • In 345 Γ— 23 = 7,935 β†’ 345 and 23 are factors; 7,935 is the product.
  • The larger number is usually called the multiplicand and the smaller one the multiplier.

Multiplication Tables β€” Quick Check

You must know your tables from 2 to 12 by heart. Here is a quick check:

Γ—678912
74249566384
84856647296
954637281108
12728496108144
Think About It: Why do we need tables? Because every big multiplication problem breaks down into smaller multiplications from the tables! When we multiply 345 Γ— 23, we actually use tables of 3, 2, and single-digit multiplication many times.

Multiplying by 10, 100, and 1000

Before we learn long multiplication, here is a powerful shortcut that makes many calculations easy:

The Zero Rule

  • Multiply by 10: Add one zero at the end of the number.
  • Multiply by 100: Add two zeros at the end of the number.
  • Multiply by 1000: Add three zeros at the end of the number.
Examples:
MultiplicationResultHow?
346 Γ— 103,460Write 346, add one zero β†’ 3460
346 Γ— 10034,600Write 346, add two zeros β†’ 34600
346 Γ— 10003,46,000Write 346, add three zeros β†’ 346000
250 Γ— 102,500Write 250, add one zero β†’ 2500
250 Γ— 10025,000Write 250, add two zeros β†’ 25000
480 Γ— 10004,80,000Write 480, add three zeros β†’ 480000

Multiplying by Multiples of 10 (20, 30, 40...)

To multiply by 20, 30, 40, etc., first multiply by the non-zero digit, then add the zero(s):

Examples:
345 Γ— 20: First, 345 Γ— 2 = 690. Then add one zero β†’ 6,900
250 Γ— 60: First, 250 Γ— 6 = 1,500. Then add one zero β†’ 15,000
178 Γ— 300: First, 178 Γ— 3 = 534. Then add two zeros β†’ 53,400
465 Γ— 40: First, 465 Γ— 4 = 1,860. Then add one zero β†’ 18,600
Image needed: A visual showing the pattern of multiplying by 10, 100, 1000. Show a number (e.g., 345) with zeros being added at the end step by step. Use arrows and colour-coded zeros (green for Γ—10, blue for Γ—100, red for Γ—1000).
Style: Clean diagram, colourful arrows, child-friendly, step-by-step visual
Size: 700Γ—350px

Standard Algorithm β€” Long Multiplication (3-Digit Γ— 2-Digit)

The standard algorithm (also called long multiplication or column method) breaks the multiplication into simple steps. Here is how it works:

Steps for 3-Digit Γ— 2-Digit Multiplication

  • Step 1: Write the 3-digit number (multiplicand) on top and the 2-digit number (multiplier) below it, aligned to the right.
  • Step 2: Multiply the multiplicand by the ones digit of the multiplier. Write this as the first partial product.
  • Step 3: Write a zero placeholder in the ones place of the next line. Then multiply the multiplicand by the tens digit of the multiplier. Write this as the second partial product.
  • Step 4: Add both partial products to get the final answer (product).

Worked Example 1: 345 Γ— 23

Let us multiply 345 Γ— 23 step by step:

      3 4 5
    Γ—   2 3
    -------
    1 0 3 5   ← 345 Γ— 3 (ones digit)
  6 9 0 0     ← 345 Γ— 2 (tens digit), shifted one place left
    -------
  7 9 3 5     ← Add: 1035 + 6900 = 7935
    

Step 1: 345 Γ— 3 = 1,035 (multiply by ones digit 3)
β†’ 5Γ—3=15, write 5 carry 1. 4Γ—3=12, +1=13, write 3 carry 1. 3Γ—3=9, +1=10, write 10.
First partial product = 1,035

Step 2: 345 Γ— 2 = 690, but since 2 is in the tens place, write it as 6,900 (add a zero)
β†’ 5Γ—2=10, write 0 carry 1. 4Γ—2=8, +1=9. 3Γ—2=6.
Second partial product = 6,900

Step 3: Add: 1,035 + 6,900 = 7,935

Therefore, 345 Γ— 23 = 7,935

Image needed: A clear step-by-step long multiplication visual showing 345 Γ— 23. Show the column layout with the multiplicand on top, multiplier below, partial products clearly labelled with arrows showing "multiply by ones" and "multiply by tens (shift left)". Final addition shown with carrying marks.
Style: Clean diagram on grid paper background, colour-coded steps (blue for first partial product, green for second), child-friendly
Size: 600Γ—500px

Worked Example 2: 567 Γ— 48

      5 6 7
    Γ—   4 8
    -------
    4 5 3 6   ← 567 Γ— 8 (ones digit)
  2 2 6 8 0   ← 567 Γ— 4 (tens digit), shifted left
    -------
  2 7 2 1 6   ← Add: 4536 + 22680 = 27216
    

Step 1: 567 Γ— 8:
β†’ 7Γ—8=56, write 6 carry 5. 6Γ—8=48, +5=53, write 3 carry 5. 5Γ—8=40, +5=45, write 45.
First partial product = 4,536

Step 2: 567 Γ— 4 = 2,268, write as 22,680 (shifted left by one place)
β†’ 7Γ—4=28, write 8 carry 2. 6Γ—4=24, +2=26, write 6 carry 2. 5Γ—4=20, +2=22, write 22.
Second partial product = 22,680

Step 3: Add: 4,536 + 22,680 = 27,216

Therefore, 567 Γ— 48 = 27,216

Worked Example 3: 904 Γ— 76

      9 0 4
    Γ—   7 6
    -------
    5 4 2 4   ← 904 Γ— 6 (ones digit)
  6 3 2 8 0   ← 904 Γ— 7 (tens digit), shifted left
    -------
  6 8 7 0 4   ← Add: 5424 + 63280 = 68704
    

Step 1: 904 Γ— 6:
β†’ 4Γ—6=24, write 4 carry 2. 0Γ—6=0, +2=2, write 2. 9Γ—6=54, write 54.
First partial product = 5,424

Step 2: 904 Γ— 7 = 6,328, write as 63,280
β†’ 4Γ—7=28, write 8 carry 2. 0Γ—7=0, +2=2, write 2. 9Γ—7=63, write 63.
Second partial product = 63,280

Step 3: Add: 5,424 + 63,280 = 68,704

Therefore, 904 Γ— 76 = 68,704

Worked Example 4: 250 Γ— 60

When the multiplier ends in zero, we can use the shortcut:

250 Γ— 60 = 250 Γ— 6 Γ— 10

250 Γ— 6: β†’ 0Γ—6=0. 5Γ—6=30, write 0 carry 3. 2Γ—6=12, +3=15. So 250 Γ— 6 = 1,500

Now multiply by 10: 1,500 Γ— 10 = 15,000

Therefore, 250 Γ— 60 = 15,000

Multiplying Larger Numbers β€” 4-Digit Γ— 2-Digit

The same method works for 4-digit numbers too! You just have more digits to multiply in each step.

Example: 2,345 Γ— 67
      2 3 4 5
    Γ—     6 7
    ---------
    1 6 4 1 5   ← 2345 Γ— 7 (ones digit)
  1 4 0 7 0 0   ← 2345 Γ— 6 (tens digit), shifted left
    ---------
  1 5 7 1 1 5   ← Add: 16415 + 140700 = 157115
    

Step 1: 2345 Γ— 7 = 16,415
β†’ 5Γ—7=35, write 5 carry 3. 4Γ—7=28, +3=31, write 1 carry 3. 3Γ—7=21, +3=24, write 4 carry 2. 2Γ—7=14, +2=16.

Step 2: 2345 Γ— 6 = 14,070, write as 1,40,700
β†’ 5Γ—6=30, write 0 carry 3. 4Γ—6=24, +3=27, write 7 carry 2. 3Γ—6=18, +2=20, write 0 carry 2. 2Γ—6=12, +2=14.

Step 3: Add: 16,415 + 1,40,700 = 1,57,115

Therefore, 2,345 Γ— 67 = 1,57,115

Think About It: Notice that when we multiply a 3-digit number by a 2-digit number, the answer can be a 4-digit or 5-digit number. When we multiply a 4-digit number by a 2-digit number, the answer can be a 5-digit or 6-digit number! Can you figure out why?

Properties of Multiplication

Multiplication has some special properties (rules) that always work, no matter what numbers you use. These properties make calculations easier and help us check our answers.

PropertyRuleExample
Commutative Property
(Order Property)
a Γ— b = b Γ— a
Changing the order of factors does not change the product.
345 Γ— 23 = 23 Γ— 345 = 7,935
126 Γ— 45 = 45 Γ— 126 = 5,670
Associative Property
(Grouping Property)
(a Γ— b) Γ— c = a Γ— (b Γ— c)
Changing the grouping of factors does not change the product.
(5 Γ— 4) Γ— 25 = 20 Γ— 25 = 500
5 Γ— (4 Γ— 25) = 5 Γ— 100 = 500
Distributive Property
(Breaking apart)
a Γ— (b + c) = aΓ—b + aΓ—c
a Γ— (b βˆ’ c) = aΓ—b βˆ’ aΓ—c
You can break one factor into parts, multiply separately, then add/subtract.
345 Γ— 23 = 345 Γ— (20 + 3)
= 345Γ—20 + 345Γ—3
= 6,900 + 1,035 = 7,935
Identity Property
(Multiplying by 1)
a Γ— 1 = a
Any number multiplied by 1 stays the same.
567 Γ— 1 = 567
9,999 Γ— 1 = 9,999
Zero Property a Γ— 0 = 0
Any number multiplied by 0 equals 0.
345 Γ— 0 = 0
99,999 Γ— 0 = 0
Image needed: A visual showing the Distributive Property of multiplication. Show 345 Γ— 23 being broken into 345 Γ— 20 + 345 Γ— 3, with rectangular area models. One large rectangle split into two smaller rectangles showing how the areas add up to the total product.
Style: Area model diagram, colour-coded sections (blue and green), labels with numbers, child-friendly
Size: 700Γ—400px
Using the Distributive Property to Multiply Mentally:

Example 1: 125 Γ— 12 = 125 Γ— (10 + 2) = 1,250 + 250 = 1,500
Example 2: 99 Γ— 45 = (100 βˆ’ 1) Γ— 45 = 4,500 βˆ’ 45 = 4,455
Example 3: 198 Γ— 25 = (200 βˆ’ 2) Γ— 25 = 5,000 βˆ’ 50 = 4,950
Example 4: 350 Γ— 14 = 350 Γ— (10 + 4) = 3,500 + 1,400 = 4,900

Estimation of Products

Estimation means finding an approximate answer quickly by rounding numbers before multiplying. This is useful to:

How to Estimate a Product

  • Step 1: Round each factor to the nearest ten, hundred, or leading digit.
  • Step 2: Multiply the rounded numbers.
  • The estimated product will be close to the actual product.
Examples:
Actual ProblemRound toEstimated ProductActual Product
489 Γ— 52500 Γ— 5025,00025,428
312 Γ— 48300 Γ— 5015,00014,976
678 Γ— 23700 Γ— 2014,00015,594
195 Γ— 41200 Γ— 408,0007,995
845 Γ— 67850 Γ— 7059,50056,615
Think About It: Meena calculated 345 Γ— 23 and got 79,350. Can she use estimation to check? Round: 350 Γ— 20 = 7,000. Her answer of 79,350 is about 10 times too big! She probably made a mistake. (The correct answer is 7,935.)

Multiplication with Zero in the Middle

When a number has a zero in the middle (like 305, 700, 408), the multiplication works the same way β€” just remember that any digit multiplied by 0 gives 0.

Example 1: 305 Γ— 42
      3 0 5
    Γ—   4 2
    -------
      6 1 0   ← 305 Γ— 2: (5Γ—2=10, 0Γ—2=0+1=1, 3Γ—2=6)
  1 2 2 0 0   ← 305 Γ— 4: (5Γ—4=20, 0Γ—4=0+2=2, 3Γ—4=12), shifted left
    -------
  1 2 8 1 0   ← Add: 610 + 12200 = 12810
    

Therefore, 305 Γ— 42 = 12,810

Example 2: 700 Γ— 86

Shortcut: 7 Γ— 86 = 602. Then add two zeros β†’ 60,200

Or the long way:

      7 0 0
    Γ—   8 6
    -------
    4 2 0 0   ← 700 Γ— 6
  5 6 0 0 0   ← 700 Γ— 8, shifted left
    -------
  6 0 2 0 0   ← Add: 4200 + 56000 = 60200
    

Therefore, 700 Γ— 86 = 60,200

Example 3: 408 Γ— 35
      4 0 8
    Γ—   3 5
    -------
    2 0 4 0   ← 408 Γ— 5: (8Γ—5=40, 0Γ—5=0+4=4, 4Γ—5=20)
  1 2 2 4 0   ← 408 Γ— 3: (8Γ—3=24, 0Γ—3=0+2=2, 4Γ—3=12), shifted
    -------
  1 4 2 8 0   ← Add: 2040 + 12240 = 14280
    

Therefore, 408 Γ— 35 = 14,280

Word Problems β€” Indian Context

Let us solve some real-life word problems that use 3-digit Γ— 2-digit multiplication:

Problem 1: Priya's school ordered 36 boxes of colour pencils. Each box contains 144 pencils. How many colour pencils were ordered in total?

Solution: Total pencils = 144 Γ— 36
    144 Γ— 36:  144 Γ— 6 = 864  |  144 Γ— 3 = 432 β†’ 4320  |  864 + 4320 = 5,184
    
Answer: 5,184 colour pencils were ordered.
Problem 2: The Rajdhani Express travels 675 km every day between Delhi and Mumbai. How many kilometres does it travel in 24 days?

Solution: Total distance = 675 Γ— 24
675 Γ— 4 = 2,700 | 675 Γ— 2 = 1,350 β†’ 13,500 | 2,700 + 13,500 = 16,200
Answer: The train travels 16,200 km in 24 days.
Problem 3: A mango farmer in Ratnagiri packs 48 crates of mangoes. Each crate holds 250 mangoes. How many mangoes does he pack in total?

Solution: Total mangoes = 250 Γ— 48
250 Γ— 8 = 2,000 | 250 Γ— 4 = 1,000 β†’ 10,000 | 2,000 + 10,000 = 12,000
Answer: The farmer packs 12,000 mangoes.
Problem 4: Arjun's father buys 52 bags of wheat at β‚Ή485 per bag for their ration shop. What is the total cost?

Solution: Total cost = β‚Ή485 Γ— 52
485 Γ— 2 = 970 | 485 Γ— 5 = 2,425 β†’ 24,250 | 970 + 24,250 = 25,220
Answer: The total cost is β‚Ή25,220.
Problem 5: A school has 38 classrooms. Each classroom has 45 desks. The school wants to buy new chairs at β‚Ή375 per chair (one chair per desk). What is the total cost of chairs?

Solution:
Step 1: Total chairs needed = 38 Γ— 45 = 1,710
Step 2: Total cost = 1,710 Γ— 375
This is a bigger multiplication! Let us use the distributive property:
1,710 Γ— 375 = 1,710 Γ— (400 βˆ’ 25) = 6,84,000 βˆ’ 42,750 = β‚Ή6,41,250
Answer: The total cost of chairs is β‚Ή6,41,250.
Image needed: A colourful illustration of an Indian market/shop scene showing: bags of rice/wheat with price tags (β‚Ή485), crates of mangoes, boxes of school supplies. A shopkeeper with a calculator. Numbers and multiplication symbols visible to show the math connection to real life.
Style: Warm, colourful cartoon illustration, Indian setting, child-friendly characters
Size: 750Γ—450px

Key Words

TermMeaning
MultiplicandThe number being multiplied (the larger number, written on top)
MultiplierThe number you multiply by (the smaller number, written below)
ProductThe answer you get after multiplying
FactorsNumbers that are multiplied together to give a product
Partial ProductThe result of multiplying by one digit of the multiplier (an intermediate step)
EstimateAn approximate answer found by rounding before calculating
CommutativeOrder does not matter: a Γ— b = b Γ— a
AssociativeGrouping does not matter: (aΓ—b)Γ—c = aΓ—(bΓ—c)
DistributiveBreak apart: aΓ—(b+c) = aΓ—b + aΓ—c
Identity (Γ—1)Any number Γ— 1 = the same number
Zero PropertyAny number Γ— 0 = 0

Key Points to Remember

  • To multiply a 3-digit number by a 2-digit number: multiply by ones digit, then by tens digit (with a zero placeholder), then add both partial products.
  • Multiplying by 10: add one zero. By 100: add two zeros. By 1000: add three zeros.
  • For multiples of 10 (20, 30, 40...): multiply by the non-zero digit first, then add the zero(s).
  • Use estimation (rounding) to quickly check if your answer is reasonable.
  • The distributive property lets you break hard multiplications into easier parts.
  • The commutative property means you can swap the order: 345 Γ— 23 = 23 Γ— 345.
  • When there is a zero in the middle of a number, multiply normally β€” 0 times anything is 0.
  • A 3-digit Γ— 2-digit product can be 4 digits (100Γ—10=1,000) or 5 digits (999Γ—99=98,901).
  • Always carry over when a single-digit multiplication gives a 2-digit result.
  • Check word problems: identify which numbers to multiply, solve, and write the answer with correct units.

Finished learning? Now test what you know!