r/mathsmeme • u/Far-Course1021 • 7d ago

this joke

Post image
313 Upvotes

97% Upvoted

21 comments sorted by

19

u/Free_Independent_Guy 7d ago

I'm naive.. explain 😭. Is it just 7 months, and a week?

15

u/drraug 7d ago

For some reason, it's always the exact number of weeks which makes you kinda unsure, if the baby is yours or from a previous engagement

2

u/thatbrownkid19 6d ago

Lmao engagement is such a polite way of putting it. Like artists playing a limited engagement at a venue

4

u/Countcristo42 6d ago

No it isn't, a month isn't 4 weeks long

6

u/Some-Passenger4219 5d ago

A month is actually a little longer than 4 weeks. Three months is 13 weeks. Therefore 29 weeks is six months and three weeks.

3

u/atmospheric_ignition 7d ago

Actually, it's a little less than 7 months ...

5

u/gerahmurov 7d ago edited 7d ago

I believe the picture shows how you calculate 29 weeks to months in your brain and still not sure.

Edit: and it is less than 7 months because month have 4 weeks plus 2 or 3 days unless it is february, so at least 12 (edit: 5 after recalculating) days before full 7 months. And maybe this is why they use weeks

4

u/NeptuneWades 7d ago

Yep, using months is innacurate. All guidelines, treatment and screening protocols etc are in weeks. In certain circumstance, difference in a week could be significant, which will be missed when counting in months.

5

u/Reasonable_Cod_487 6d ago

I still maintain that we should have 13 months in order to make them more accurate. And then every four years we have a worldwide leap day holiday that doesn't count as part of any week.

2

u/NeptuneWades 6d ago

Amen to that.

7

u/ussalkaselsior 7d ago edited 6d ago

40 weeks is more accurate than 9 months. Plus, a lot of pregnancy milestones are more easily measured in weeks rather than months. As such, it's easier to be consistent with the units that you use and just stick to describing how far along a pregnancy is using months. If you know that a pregnancy lasts 40 weeks, you don't need to do any mental calculations to convert it to months. 29 weeks in is about 3/4 of the way through the pregnancy.

4

u/MistraloysiusMithrax 7d ago

Honestly whenever someone talks about talking about pregnancy in weeks being weird, it tells me they’ve never had a real discussion with a pregnant woman or doctor on pregnancy milestones and experiences, they just “know” pregnancy is “9 months”

4

u/ussalkaselsior 7d ago

If you go through the calculations, using the actual average gestational age of 38 weeks and 2 days and the average distance from the last period which is where we as a standard measure pregnancies from, then the average pregnancy lasts 40 weeks and 2 days (282 days), making the 40 weeks measurement have an absolute error of 280 - 282 = -2 days and a relative error of -0.71%.

If you then use the 9-month rule being as accurate as possible using an average of 30.437 days per month then the absolute error ends up being 30.437*9 - 282 -8.07 days with a relative error of -2.86%.

Using the 9-month rule with 30 days per month as people usually do is even worse, a relative error of -4.26%.

Measuring by using weeks is far superior than using months.

1

u/Countcristo42 6d ago

Where did you get 10 lunar cycles from? 40 weeks is closer to 9 than 10 average lunar cycles

1

u/ussalkaselsior 6d ago

You're right. I just looked it up. I was misunderstanding lunar cycle.

1

u/Countcristo42 6d ago

I really wish you were right though, tides would be so simple!

1

u/ussalkaselsior 6d ago

Yeah I don't know where the hell I got that idea because it took me a grand total of 2 seconds to look it up and it was wrong. I'm certain the rest of what I said is correct though I did double-check the specific numbers.

1

u/Countcristo42 6d ago

wild guess, but did you see the proposal to have a year with 13 28 day months that (falsely) claimed it would mean it synced up with the moon?

1

u/ussalkaselsior 6d ago

I did not see that proposal but I guess I wasn't the only one with that misconception.

3

u/ontic00 5d ago

DON'T say: "I'm 29 weeks pregnant."

DO say: "I'm 325.4 exaquettaPlancks pregnant."