Summarize the following:
Write the problem as a long-division problem. Just like a simpler division problem, you can start by looking at the smaller number, and asking "Does it fit into the first digit of the larger number?" Let's say you're solving 3472 15. Ask "Does 15 fit into 3?" Since 15 is definitely larger than 3, the answer is "no," and we move on to the next step. Since you can't fit a two-digit number into a one-digit number, we'll look at the first two digits of the dividend instead, just like we would in a regular division problem. If you still have an impossible division problem, you'll need to look at the first three digits instead, but we don't need to in this example: Does 15 fit into 34? Yes, it does, so we can start calculating the answer. (The first number doesn't have to fit perfectly, it just needs to be smaller than the second number.) Find out exactly how many times the first number fits into the other. You might know the answer already, but if you don't, try making a good guess and checking your answer with multiplication. We need to solve 34 15, or "how many times does 15 go into 34"? You're looking for a number you can multiply with 15 to get a number less than 34, but pretty close to it: Does 1 work? 15 x 1 = 15, which is less than 34, but keep guessing. Does 2 work? 15 x 2 = 30. This is still less than 34, so 2 is a better answer than 1. Does 3 work? 15 x 3 = 45, which is greater than 34. Too high! The answer must be 2. If you set this up like a long division problem, this should feel familiar. Since you were calculating 34 15, write the answer, 2, on the answer line above the "4." This is the same as a normal long division problem, except we'll be using a two-digit number. Your answer was 2 and the smaller number in the problem is 15, so we calculate 2 x 15 = 30. Write "30" underneath the "34." The last thing you wrote went underneath the original larger number (or part of it). Treat this as a subtraction problem and write the answer on a new line underneath. Solve 34 - 30 and write the answer underneath them on a new line. The answer is 4. This 4 is still "left over" after we fit 15 into 34 two times, so we'll need to use it in the next step. Just like a regular division problem, we're going to keep calculating the next digit of the answer until we've finished. Leave the 4 where it is and bring down the "7" from "3472" to make 47. To get the next digit, just repeat the same steps you did above for the new problem. You can use guesswork again to find the answer: We need to solve 47 15: 47 is bigger than our last number, so the answer will be higher. Let's try four: 15 x 4 = 60. Nope, too high! We'll try three instead: 15 x 3 = 45. Smaller than 47 but close to it. Perfect. The answer is 3, so we'll write that about the "7" on the answer line. (If we ended up with a problem like 13 15, with the first number smaller, we would need to bring down a third digit before we could solve it.) Repeat the long division steps we used before to multiply our answer by the smaller number, write the result underneath the larger number, and subtract to find the next remainder. Remember, we just calculated 47 15 = 3, and now we want to find what's left over: 3 x 15 = 45, so write "45" underneath the 47. Solve 47 - 45 = 2. Write "2" underneath the 45. As before, we bring down the next digit from the original problem so we can solve the next division problem. Repeat the steps above until you find every digit in the answer. We've got 2 15 as our next problem, which doesn't make much sense. Bring down a digit to make 22 15 instead. 15 goes into 22 one time, so we write "1" at the end of the answer line. Our answer is now 231. One last subtraction problem to find the final remainder, then we'll be done. In fact, if the answer to the subtraction problem is 0, you don't even need to write a remainder at all. 1 x 15 = 15, so write 15 underneath the 22. Calculate 22 - 15 = 7. We have no more digits to bring down, so instead of more division we just write "remainder 7" or "R7" at the end of our answer. The final answer: 3472 15 = 231 remainder 7
Look at the first digit of the larger number. Look at the first two digits. Use a little guesswork. Write the answer above the last digit you used. Multiply your answer by the smaller number. Subtract the two numbers. Bring down the next digit. Solve the next division problem. Continue using long division. Find the last digit. Find the remainder.