Multiplication by 1-digit Number

How to Multiply by a 1-Digit Number

We will learn how to multiply any number by a one-digit number.

1. Multiply 2154 and 4.

Solution:

Step I: Arrange the numbers vertically.

Step II: First multiply the digit at the ones place by 4.

4 × 4 = 16 = 1 ten + 6 ones

Write 6 in the ones column and carry 1 ten to tens place.

Step III: Multiply the digit at the tens place by 4.

5 × 4 = 20 tens

20 + 1 (carried) = 21 tens = 2 hundreds + 1 ten

Write 1 in ten place and carry 2 hundreds to hundreds place.

Step IV: Multiply the digit at hundreds place by 4.

1 hundred × 4 = 4 hundreds

4 hundreds + 2 hundreds (carried) = 6 hundreds

Write 6 in hundreds place.

Step V: Multiply the digit at thousands place by 4.

2 thousands × 4 = 8 thousands

Write 8 in thousands place.

2. Multiply 7325 and 9.

Solution:

Step I: Arrange the numbers vertically.

Step II: First multiply the digit at the ones place by 9.

5 × 9 = 45 = 4 ten + 5 ones

Write 5 in the ones column and carry 4 tens to tens place.

Step III: Multiply the digit at the tens place by 9.

2 × 9 = 18 tens

18 + 4 (carried) = 22 tens = 2 hundreds + 2 ten

Write 2 in ten place and carry 2 hundreds to hundreds place.

Step IV: Multiply the digit at hundreds place by 9.

3 × 9 = 27 hundreds

27 hundreds + 2 hundreds (carried) = 29 hundreds = 2 thousands + 9 hundreds

Write 9 in hundreds place and carry 2 thousands to thousands place.

Step V: Multiply the digit at thousands place by 9.

7 thousands × 9 = 63 thousands

63 thousands + 2 thousands (carried) = 65 thousands = 6 ten thousands + 5 thousands

Write 5 in thousands place and 6 ten thousands in ten thousands place.

Questions and Answers on Multiplication by 1-digit Number:

1. Multiplication of 4-Digit Numbers by 1-Digit Number by column method.

(i) 2031 × 3 = __________

(ii) 1347 × 2 = __________

(iii) 5120 × 4 = __________

(iv) 1227 × 7 = __________

(v) 2310 × 6 = __________

(vi) 3127 × 5 = __________

(vi) 4081 × 8 = __________

(vi) 5526 × 9 = __________

(ix) 8052 × 3 = __________

Answers:

(i) 6093

(ii) 2694

(iii) 20480

(iv) 8589

(v) 13860

(vi) 15635

(vi) 32648

(vi) 49734

(ix) 24156

2. Multiply the given 4-Digit Numbers by 1-Digit Number horizontally. Start from right. One has been done for you.

(ii) 2121 × 3 = __________

(iii) 3004 × 2 = __________

(iv) 9865 × 1 = __________

Answers:

(ii) 6363

(iii) 6008

(iv) 9865

4th Grade Math Activities

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