Page 37 - Start Up Mathematics_5

Example 20: Divide 87,653 by 23 and check your answer.

Solution: 3 Step 1: Since 23 is a 2-digit number, we take the first two
23 8 7 6 5 3 digits of the dividend.

– 6 9 Since 87 > 23, we will divide.
1 8 Now the first digit of 23 is 2 and 87 is 8.

8 ÷ 2 = 4. Thus, the quotient can be 4.

To check, multiply 23 by 4.
23 × 4 = 92 > 87

23 × 3 = 69 < 87
Write 3 at the thousands place of the quotient and
69 below 87 and subtract.
87 – 69 = 18
3 8
23 8 7 6 5 3 Step 2: Bring down 6 of the dividend.
– 6 9 ↓ 18 ÷ 2 = 9. Thus, the quotient can be 9.

1 8 6 To check, multiply 23 by 9.

– 1 8 4 23 × 9 = 207 > 186

2 23 × 8 = 184 < 186
Write 8 at the hundreds place of the quotient and
184 under 186 and subtract.

3 8 1 186 – 184 = 2

23 8 7 6 5 3 Step 3: Bring down 5 and write after 2.

– 6 9 ↓ Since 23 < 25, write 1 at the tens place of the

1 8 6 quotient and 23 below 25 and subtract.
– 1 8 4 25 – 23 = 2

2 5
– 2 3
2
3 8 1 1
23 8 7 6 5 3 Step 4: Bring down 3 and write after 2.

– 6 9 ↓ 23 × 1 = 23

1 8 6 Write 1 at the ones place of the quotient and 23
– 1 8 4 under 23 and subtract.
2 5
23 – 23 = 0
– 2 3
2 3
– 2 3
0

So, 87,653 ÷ 23 = 3,811 and remainder = 0.

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