Is 309 divisible by two?
When we see this phrase “divisible by,” it’s asking “can you divide 309 by two and have no remainder?” “Is it evenly divisible by two?” would be another way to say it. One way to solve this problem would be to try it. Try to divide 309 by two. How many times does two go into three? One time. One times two is two. Then, we need to subtract. Three minus two equals one. Bring down the next digit to the right, which is a zero.
So far so good, now we’re going to ask the question “how many times does two go into 10?” Two can go into 10 five times. Five times two equals 10. And now we subtract. 10 minus 10 equals zero. Bring down the nine and then we ask the question “how many times does two go into nine?” Two can go into nine four times. Four times two equals eight. Nine minus eight equals one. And there is nothing left to bring down. This one at the bottom of our division problem is called the remainder.
We have a remainder of one and that tells us that 309 is not evenly divisible by two. The answer to the question “is 309 divisible by two?” is no.
There is also another way to think about divisibility by two. To check for divisibility by two, you look at the digit in the ones place or in the units place. If that digit is even, then the whole number is divisible by two. If that value is odd, then that number is not divisible by two. Because nine is an odd number, we can know that the number 309 is not divisible by two.