Number Dojo Level: 16
Dividing Whole Numbers
Once again, we need to know some basic definitions or terms within a division problem. The dividend, in the world of finance, is passive income from your investments. In math, it's the big number you start with--the number you're dividing into smaller pieces. The divisor is the number you're dividing by, and the quotient is the answer.
- Work from left to right. See how many times the divisor "goes into" the first digit of the dividend. If it fits, write that number down and remember any remainder; then mentally put the remainder in front of the next digit to create a 2-digit number. If it doesn't fit, instead look at the first two digits of the dividend and move on to step 2.
- See how many times the divisor "goes into" that 2-digit number. If it fits, write how many times it fits & remember any remainder; then mentally put the remainder in front of the next digit.
- Repeat and continue until you have moved through each digit of the dividend.
Example 1: 730 ÷ 5
- See how many times 5 goes into the 7. The answer is 1, with a remainder of 2. Write down the 1 and mentally put the 2 in front of the 3 to get 23.
- See how many times 5 goes into 23. 5 x 4 = 20 and 5 x 5 = 25 (too large), so write down the 4 (after the 1) and put the remainder of 3 in front of the 0 to get 30.
- See how many times the 5 goes into 30: 6 times. Write the 6 at the end. Your quotient is 146.
Example 2: 268 ÷ 4
- See how many times 4 goes into the 2. Since it doesn't fit, look at the 26 instead.
- See how many times 4 goes into 26. We know that 4 x 6 = 24 and 4 x 7 = 28. 28 is too big, so we use the 6. There is a remainder of 2.
- Now put that 2 remainder in front of the 8 to make 28. You've already established that 4 goes into 28 -- 7 times. Write that 7 after your 6 to get your quotient: 67.
Example 3: 114 ÷ 19
- Sometimes the divisor is so large that you can't divide into the first digit or the first two digits of the dividend. In cases like this, I save time by estimating.
- Since I know that 19 is almost 20, I can quickly determine that 20 goes into 114 -- 5 times. (5 x 20 = 100). 5 is too small to be our quotient.
- 6 x 20 = 120, so the answer could be 6. I check my answer by multiplying 6 x 19. My brain does that from left to right: 6 x 10 = 60; 6 x 9 = 54. 60 + 54 = 114 (our dividend). The quotient is 6.
How NOT to divide whole numbers: