Plant Reproduction

Multiplication of 2-digit and 3-digit Numbers

Multiplying 2-digit number by 1-digit number

Example 3

Multiply 24 by 2

Step 1: Multiply 4 ones by 2.
4 ones ⨯ 2 = 8 ones
Write 8 in ones column.
Step 2: Multiply 2 tens by 2.
2 tens ⨯ 2 = 4 tens
Write 4 in tens column.

Exercise 6.5

A. Multiply.

Multiplying 3-digit number by 1-digit number

Example 4

Multiply 121 by 4

Step 1: Multiply 1 one by 4. 1 one ⨯ 4 = 4 ones.
Write 9 in the ones column.
Step 2: Multiply tens by 3. 2 tens ⨯ 3 = 6 tens.
Write 6 in the tens column.
Step 3: Multiply hundreds by 3. 1 hundred ⨯ 3 = 3
hundreds. Write 1 in the hundreds column.

Exercise 6.6

A. Multiply.

Multiplying 2-digit number by 1-digit number with regrouping

Example 5

Multiply 44 by 3

Step 1: Multiply 4 ones by 3. 4 ones ⨯ 3 = 12 ones
12 ones = 1 ten and 2 ones
Write 2 in the ones column. Carry over 1 to the tens column.
Step 2: Multiply 4 tens by 3. 4 tens ⨯ 3 = 12 tens
12 tens + 1 ten = 13 tens
13 tens = 1 hundred and 3 tens.
Write 1 in the hundreds column and 3 in tens

Exercise 6.7

A. Multiply.

Multiplying 3-digit number by 1-digit number with regrouping

Example 6

Multiply 257 by 3

Step 1: Multiply 7 ones by 3. 7 ones ⨯ 3 = 21 ones
21 ones = 2 tens and 1 one. Write 1 in the ones
column and carry over 2 to the tens column.
Step 2: Multiply 5 tens by 3. 5 tens ⨯ 3 = 15 tens
15 tens + 2 tens = 17 tens. 17 tens = 1 hundred
and 7 tens. Write 7 in the tens column and carry over 1 to the hundreds column.
Step 3: Multiply 2 hundreds by 3. 2 hundred ⨯ 3 = 6 hundreds. 6 hundreds + 1 hundred = 7 hundred.
Write 4 in the hundreds column.

Exercise 6.8

A. Multiply.

Word problems

There are 5 rows and 6 columns of chairs in our class. How many students are there in my class?

Exercise 6.9

  1. I solve 6 Sudokus every day. How many Sudokus will I solve in 7 days?
  2. A shopkeeper has 8 packets of erasers. Each packet has 12 erasers. How many erasers are there in all?
  3. 5 teams came to play a basketball tournament in our school. Each team has 7 players. Find the number of players participating in the tournament.
  4. There are 4 weeks in one month. Find the number of weeks in 12 months.
  5. A box has 220 apples. How many apples are there in 4 such boxes?