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Example 1.61 from Prealgebra, 1.5 Divide Whole Numbers
Divide Whole Numbers: example 1.61
Divide Check by multiplying:
Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.
Solution
Let's rewrite the problem to set it up for long division. Divide the first digit of the dividend, 2, by the divisor, 4. Since 4 does not go into 2, we use the first two digits of the dividend and divide 25 by 4. The divisor 4 goes into 25 six times. We write the 6 in the quotient above the 5. Multiply the 6 in the quotient by the divisor 4 and write the product, 24, under the first two digits in the dividend. Subtract that product from the first two digits in the dividend. Subtract . Write the difference, 1, under the second digit in the dividend. Now bring down the 9 and repeat these steps. There are 4 fours in 19. Write the 4 over the 9. Multiply the 4 by 4 and subtract this product from 19. Bring down the 6 and repeat these steps. There are 9 fours in 36. Write the 9 over the 6. Multiply the 9 by 4 and subtract this product from 36. So . Check by multiplying. It equals the dividend, so our answer is correct.
Your turn
The book's Try It right after this example: same idea, new numbers. Only the answer is given.
Divide. Then check by multiplying:
How did it go?