Remainders

Hello, and welcome to Myriora Maths! Share fourteen sweets between four children. Each child gets three, but two are left over. What do we do with the two? Let's find out!

Deal them out fairly, one at a time. One round: four sweets gone. Two rounds: eight. Three rounds: twelve. Now there are only two left. That's not enough to give everyone another one. So each child gets three, and two are left over.

We write it like this: fourteen divided by four is three, remainder two. The r stands for remainder: the bit that's left over. Check it: three fours are twelve, add the two left over, and you're back to fourteen.

The remainder must always be smaller than the number you divide by. Why? If four or more were left over, every child could have one more! So if you get fourteen divided by four is two, remainder six, keep sharing. Six is enough for another round.

In word problems, you have to think about the remainder. Thirty children go on a trip. Each minibus holds eight. How many minibuses do they need? Thirty divided by eight is three, remainder six. Three buses would leave six children behind! So we need one more: four minibuses. Here we round up.

Sometimes you round down. You have twenty pounds. Books cost three pounds each. How many can you buy? Twenty divided by three is six, remainder two. You can buy six books, and you have two pounds left. You can't buy part of a book! So here we round down.

Let's try one together. Twenty-five eggs go into boxes of six. How many boxes can you fill right to the top? Say it out loud!

Twenty-five divided by six is four, remainder one. Four boxes are full, and one egg is left over. So the answer is four full boxes!

Here's a question that catches lots of people. Thirty children, and minibuses that hold eight: how many minibuses? Some people work out three, remainder six, and just say three. But then six children stay at home! You need four minibuses.

Your turn! Twenty-two children are going camping. Each tent sleeps four. How many tents do they need? Pick the right card. You've got fifteen seconds, or pause the video. Go!

Time's up! Twenty-two divided by four is five, remainder two. Five tents leave two children with nowhere to sleep. So they need six tents!

Quick review. The remainder is what's left over. It must be smaller than the number you divide by. To check, times back, then add the remainder. And in word problems, think: round up if everyone needs a place, and round down if you can't use a part. See you next time!