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DiviSion by A 1-DiGit numbEr (WitH rEGroupinG)

Division of a 2-digit number

Example 1. Divide 78 by 2.

Solution.

Step 1. Arrange the numbers in long division form. t o
Step 2. Divide the tens by 2. 3 9 (Q)

7 tens ÷ 2 = 3 tens 2 7 8
Write 3 in the tens place in the quotient. – 6

Step 3. Multiply the divisor and the quotient. 1 8

3 tens × 2 = 6 tens – 1 8
0 (R)
Write 6 in the tens place below the dividend.

Subtract the digits in the tens column. 7 – 6 = 1

Step 4. Bring down 8 ones and regroup with 1 ten. 1 ten + 8 ones = 18 ones.
Step 5. Repeat from step 2 to step 3.

Divide: 18 ÷ 2 = 9 (Q), Multiply: 2 × 9 = 18, Subtract: 18 – 18 = 0 (R)
Thus, quotient (Q) = 39, remainder (R) = 0.

Checking

(Quotient × Divisor) + Remainder = Dividend “Dividing a number
(39 × 2) + 0 = 78 by itself gives the

78 + 0 = 78 quotient 1”.
Thus, the division is correct.

Division of a 3-digit number

Example 2. Divide 289 by 6.

Solution. Keep in Mind

Step 1. Divide the hundreds. When the first digit of the
2 cannot be divided by 6. t o dividend is smaller than

So, regroup hundreds and tens. 4 8 (Q) the divisor, we do not put
2 hundreds + 8 tens = 28 tens 6 2 8 9 0 in the quotient. Instead,

Step 2. Divide 28 tens by 6 – 2 4 we take the first two digits
together and then divide.
28 ÷ 6, quotient = 4 tens 4 9
Step 3. Multiply: 4 × 6 = 24 tens – 4 8
Subtract: 28 – 24 = 4 tens 1 (R)

100 Mathematics 3