“Do you have homework tonight?”
“Yes. It’s quite hard.”
“Oh.” We are in our local pizzeria, for a change. The homework thing, after a year of unschooling, comes as a bit of a shock to both of us. “What’s the problem?”
“It’s multiplying decimals.”
“Oh,” I say. “I thought you could do that.” He taught himself decimals and percentages. That was nice, because it meant I didn’t have to fight with him about it.
“But you’re not the best at long multiplication, are you?” He taught himself that too. Less said the better, perhaps.
“It’s not that,” he says. “It’s just really confusing. Anyway, it’s not due in till Wednesday so I don’t need to do it tonight.”
It turns out that the elusive homework is not multiplying decimals. It is multiplying and dividing fractions. And the internet we are stealing from the restaurant across the way is very, very patchy.
These sums looks quite difficult to me. They have scary numbers in them.
6/7 x 8/15
They also have ones where you need to cancel the numbers out.
2/9 x 9/11.
Oh god. And dividing. I remember dividing fractions. I remember weeks and weeks of dividing sodding fractions.
“I remember the bottom one’s called the denominator. But what about the top one, Mum?”
The internet is out. “I can’t remember, honey. It was a long time ago.”
His brow is furrowed as he stares intently at the worksheet.
“Oooh! You’ve done the first few! Well done!” I say, in my very best nice Mummy voice. “What’s the problem?”
“Shut up,” he says. “I’m trying to concentrate.”
Time passes. His lips move silently.
“But what’s the problem?” I ask again. “Why don’t you just do whatever you did on the first ones?”
“Because I can’t remember how I did it, alright?!”
“I really think you should show your working,” I begin…
“I don’t need to,” he says. “I do it in my head.”
“Yes,” I say, and some primordial memory flickers.
I am fairly sure I have been on Z’s end of pretty much this exact conversation with my father, almost to the word, 25 years ago, or thereabouts. And, I realise with a sinking feeling, for about another five years after that.
“And you’ve got this sum, and this sum, and this sum, wrong by doing it in your head,” I hear myself saying, in almost the exact tone of barely controlled irritation my father used with me.
I take a deep breath. “If you show your workings and get the wrong answer, the teacher will know you were on the right lines.”
I realise I am doomed to replay these conversations from the other side of the fence, in some sort of parenting Groundhog Day.
“Can’t I just do a formula?” he asks.
“No,” I say, as I did the last time we had this conversation. “A formula is a great idea, but it doesn’t show the teacher your workings.”
“No one in school shows their workings. The teacher doesn’t care.” I am not qualified to comment on the truth of this.
He scribbles vigorously. “There!” he says. “I’ve written a formula.”
“That’s not a formula,” I say. “Formulas have letters in them. They’re algebraic.”
I realise turning multiplication of fractions into a formula would be a most excellent learning activity, virtually algebra lessons in fact. Then I try to think of how to do it and my brain turns into a nest of snakes.
“It IS a formula,” he says.
“It is NOT a formula. It’s an example of a sum. Now sit down, do your homework and SHOW YOUR F*CKING WORKINGS.”
I’m shouty, I’m swearing and we haven’t even started on dividing the bastard fractions.
We agree to leave that till tomorrow.
Some lovely people have told me on Twitter that “the number you divide by, turn upside down and multiply.” I have told Z this, also.
“I know how to divide fractions,” he tells me chirpily after I pick him up from the friend’s house where he has spent the afternoon. “I asked MJ to show me.”
“The Korean kid?”
“Yeah. He’s good at maths. He was kind of busy, actually. He had to help both me and K.”
We find the worksheet. I start to cook. I realise he has written nothing.
“What’s the problem?” I ask, wearily.
“I can’t remember how to do it.”
“The number you divide by, turn upside down and multiply,” I say, helpfully.
“Stop saying that,” he says.
“It’s the rule for dividing fractions,” I say.
“I know THAT,” he says balefully. “I’ve forgotten how to multiply them.”
“Well,” I say, writing down a sample sum.
“Why are you writing that down?” he asks me accusingly. “Why aren’t you helping me with my homework?”
I take a deep breath. “I am writing down a sum so I can show you how to do it.”
“You know why I don’t like doing fractions?” he asks, heatedly. “Because I have a LIFE. And a SOCIAL LIFE. And I want to get through this AS QUICKLY AS POSSIBLE.”
We stare at the worksheet.
“The thing about dividing fractions,” I begin confidently. “Is that they get, umm…”
Bigger? Is that right? Can that possibly be right? Surely dividing makes things smaller, not bigger?
I begin again. “It’s like negative numbers, ummm, they get, ummm, they don’t behave like you’d expect them, because when you, ummm….”
I pause for thought. “OK. Let’s imagine we’re dividing a fifth by a tenth. The answer is going to be, umm… err…”
“OK, so if we were doing it as decimals, what would a fifth be and what would a tenth be?”
“0.2 and 0.1,” he says.
“Exactly!” I say. “So if we divide 0.2 by 0.1 the answer would be, ummm…. Whereas if we multiply, the answer, ummm…”
He looks at me irritably. “You can’t actually do this, can you, mum?”
“Percentages!” I say. “What’s a fifth and a tenth as percentages?”
“20% and 10%.”
“Exactly! And 20% divided by 10% is, umm…”
His voice drips with a sarcasm not entirely appropriate for his age.
“I think the answer you are looking for is ‘two’.”
It gets shouty. Quelle bloody surprise.
Or, as a friend of mine puts it, “They should just call homework ‘shouty time’.”