What is the Formal Method of Multiplication?

Hello, Year 4! Today, we’re going to learn about the formal method of multiplication. This method helps us multiply larger numbers easily and accurately.

What Do We Need to Know?

  1. Place Value: Each digit in a number has a value depending on its position (units, tens, hundreds, etc.).
  2. Multiplication Basics: Multiplying means adding a number to itself a certain number of times. For example, (3 \times 4) means adding (3) four times: (3 + 3 + 3 + 3).

Steps to Multiply Using the Formal Method

Let’s use an example to understand this better. We’ll multiply (23) by (4).

  1. Set it up:Write the numbers vertically. The larger number goes on top, and the smaller number goes below it. 23 × 4
  2. Multiply the units:Multiply the bottom number by the units place of the top number.
    • (4 \times 3 = 12)
    • Write down (2) (the units) and carry over (1) (the tens).
    23 × 4 ------ 2 (this is from 12, write 2 here) carry 1
  3. Multiply the tens:Now, multiply the bottom number by the tens place of the top number, and add the carry.
    • (4 \times 2 = 8) and then add the (1) we carried over: (8 + 1 = 9).
    • Write (9) down.
    23 × 4 ------ 92

So, (23 \times 4 = 92).

Key Rules

  • Always start multiplying from the rightmost digit (units).
  • Don’t forget to carry over if the result is 10 or more.
  • Write down your final answer carefully.

Tips and Tricks

  • Practice with smaller numbers first to build confidence.
  • Use grid paper to keep your numbers aligned.
  • Check your answers by reversing the multiplication (divide the answer by one of the numbers).

Practice Questions

Easy Level Questions

  1. (12 \times 2)
  2. (15 \times 3)
  3. (21 \times 1)
  4. (34 \times 2)
  5. (42 \times 1)
  6. (11 \times 4)
  7. (23 \times 3)
  8. (30 \times 2)
  9. (10 \times 5)
  10. (5 \times 6)
  11. (16 \times 2)
  12. (22 \times 1)
  13. (14 \times 2)
  14. (33 \times 1)
  15. (20 \times 3)
  16. (25 \times 1)
  17. (40 \times 2)
  18. (18 \times 1)
  19. (50 \times 2)
  20. (6 \times 4)

Medium Level Questions

  1. (24 \times 5)
  2. (36 \times 3)
  3. (45 \times 2)
  4. (27 \times 4)
  5. (32 \times 3)
  6. (64 \times 2)
  7. (23 \times 6)
  8. (15 \times 5)
  9. (42 \times 4)
  10. (21 \times 7)
  11. (18 \times 5)
  12. (30 \times 4)
  13. (50 \times 3)
  14. (60 \times 2)
  15. (75 \times 2)
  16. (14 \times 7)
  17. (33 \times 3)
  18. (22 \times 5)
  19. (19 \times 6)
  20. (48 \times 3)

Hard Level Questions

  1. (123 \times 4)
  2. (234 \times 5)
  3. (156 \times 3)
  4. (245 \times 6)
  5. (312 \times 4)
  6. (156 \times 7)
  7. (234 \times 8)
  8. (145 \times 9)
  9. (267 \times 3)
  10. (189 \times 5)
  11. (135 \times 6)
  12. (276 \times 4)
  13. (423 \times 2)
  14. (512 \times 3)
  15. (643 \times 2)
  16. (134 \times 8)
  17. (299 \times 5)
  18. (456 \times 2)
  19. (378 \times 6)
  20. (194 \times 7)

Answers

Easy Level Answers

  1. (24)
  2. (45)
  3. (21)
  4. (68)
  5. (42)
  6. (44)
  7. (69)
  8. (60)
  9. (50)
  10. (30)
  11. (32)
  12. (22)
  13. (28)
  14. (33)
  15. (60)
  16. (25)
  17. (80)
  18. (18)
  19. (100)
  20. (24)

Medium Level Answers

  1. (120)
  2. (108)
  3. (90)
  4. (108)
  5. (96)
  6. (128)
  7. (138)
  8. (75)
  9. (168)
  10. (147)
  11. (90)
  12. (120)
  13. (150)
  14. (120)
  15. (150)
  16. (98)
  17. (66)
  18. (110)
  19. (114)
  20. (144)

Hard Level Answers

  1. (492)
  2. (1170)
  3. (468)
  4. (1470)
  5. (1248)
  6. (1092)
  7. (1872)
  8. (1305)
  9. (801)
  10. (945)
  11. (810)
  12. (1104)
  13. (846)
  14. (1536)
  15. (1286)
  16. (1072)
  17. (1495)
  18. (912)
  19. (2268)
  20. (1358)

Now you have a great understanding of the formal method of multiplication! Keep practicing with these questions, and you’ll get even better at it!