Mathematics -- Class 4

Topic: Multiplication (2-Digit and 3-Digit Numbers)
Name: ____________________________Class: 4Date: ________________
Learning Objectives
Quick Recap

In Class 3, you learned that multiplication is repeated addition. You learned tables up to 10. Now let us go further!

In Class 4, we will multiply bigger numbers -- 2-digit and 3-digit numbers. We will also learn to multiply a 2-digit number by another 2-digit number.

Multiplying Bigger Numbers

2-Digit x 1-Digit (with carrying)

To multiply a 2-digit number by a 1-digit number, multiply each digit starting from the right (ones place).

Example 1: Find 23 x 4

Step 1: Multiply the ones. 3 x 4 = 12. Write 2, carry 1.

Step 2: Multiply the tens. 2 x 4 = 8. Add the carry: 8 + 1 = 9.

Answer: 23 x 4 = 92

Example 2: Find 47 x 6

Step 1: 7 x 6 = 42. Write 2, carry 4.

Step 2: 4 x 6 = 24. Add carry: 24 + 4 = 28.

Answer: 47 x 6 = 282

3-Digit x 1-Digit

Example 3: Find 235 x 4

Step 1: 5 x 4 = 20. Write 0, carry 2.

Step 2: 3 x 4 = 12. Add carry: 12 + 2 = 14. Write 4, carry 1.

Step 3: 2 x 4 = 8. Add carry: 8 + 1 = 9.

Answer: 235 x 4 = 940

2-Digit x 2-Digit

Example 4: Find 24 x 13

Step 1: Multiply 24 by 3 (ones digit of 13): 24 x 3 = 72.

Step 2: Multiply 24 by 10 (tens digit of 13): 24 x 10 = 240.

Step 3: Add: 72 + 240 = 312.

Always start from the ones place and work left. Do not forget to carry!

Key Words and Meanings
WordMeaning
FactorThe numbers we multiply together
ProductThe answer of a multiplication
CarryMoving extra tens to the next column
EstimateA rough answer to check if your exact answer is correct

Mathematics -- Class 4 (continued)

Topic: Multiplication -- Key Points and Practice
Key Points to Remember
Practice Questions

A. Multiply (2-Digit x 1-Digit)

  1. 34 x 5 =
  2. 56 x 7 =
  3. 78 x 4 =
  4. 63 x 8 =
  5. 49 x 9 =

B. Multiply (3-Digit x 1-Digit)

  1. 125 x 6 =
  2. 348 x 3 =
  3. 207 x 5 =
  4. 456 x 4 =

C. Multiply (2-Digit x 2-Digit)

  1. 15 x 12 =
  2. 23 x 14 =
  3. 36 x 21 =

D. Multiple Choice Questions

  1. What is 45 x 6?
    (a) 240(b) 260(c) 270(d) 280
  2. What is 100 x 7?
    (a) 70(b) 107(c) 700(d) 7000

E. Word Problems

  1. A school has 28 classrooms. Each classroom has 35 chairs. How many chairs are there in all?
  2. A factory makes 245 toys every day. How many toys does it make in 7 days?
  3. There are 12 rows of trees. Each row has 15 trees. How many trees are there?
Think and Do -- Fun Activity

Estimate and Check: First estimate the answer by rounding, then calculate the exact answer. How close was your estimate?

ProblemEstimate (Round)Exact AnswerClose?
38 x 5
72 x 4
156 x 3