The maths skills I learned at school (as in up to GCSE) are used pretty much daily by me. Not so much quadratic equations, but plenty of core skills and they really are so useful in every area of life, including work. Thought I’d include several below.
I studied a social science at uni, and most of my classmates were most aggrieved when they discovered in our second year that they had to use maths skills (for research, statistical analysis etc) and couldn’t just debate varying philosophies for three years 
My fondness for statistics came in very handy at that point.
In my personal life, I use maths constantly. I’m the ‘life admin’ person in our household. We have three bank accounts, I have regular payments to make and not all are automatic (like DDs) so I have to work them out and make sure they’re covered. If you ever claim any benefits, having decent maths skills can make a real difference. The letters you get and entitlements and so on can be so unbelievably convoluted. I’ve avoided huge overpayments by having calculated in advance what my entitlements would be for a change in our circumstances (online calculators don’t always capture everything). Equally, I have been able to demonstrate how I’ve been underpaid using mainly a solid understanding of money in versus money out and what balance remains over a period of time. The council actually asked if I was an accountant 
I work in HR. In theory I shouldn’t personally have to work out entitlements for things like annual leave, maternity pay etc as we have a system to do that, but in practice I do because the system will only work that out when it’s needed - you can’t find out a theoretical sum in advance. So instead, whether in advising other people or for myself and my team as a manager, I will work through the various entitlements, pay uplifts, and so on to get a rough figure so that I/they know what to expect.
In the past I used to have to work out the payroll myself, which was particularly important for ensuring we paid the right amount of employer’s NI contributions. I also had to work out annual leave entitlement, which would get more interesting with part time working patterns (eg working out what 0.72 of an hour is and so on).
When I worked in retail, we would often have to compensate people or discount something (eg a slightly damaged item) which would involve manually working out discounts to then apply them. We also had to calculate the float in the tills in the morning and cash up the tills every night by hand, entering these into the point of sale machines, and investigate if there was a discrepancy (basically we did all of the counting, the machine just told us if there was a discrepancy). This wasn’t long ago and was for a major department store.
When I worked in sales, I would go to trade events and would have to calculate things like bulk discounts (eg unit price decreases dependent on number of units purchased), VAT exemptions (some clients had to pay VAT, others didn’t), estimated shipping costs (dependent on weight and distance), and so on, on the spot with clients.
A lot of these are fairly simple maths skills - multiplying, dividing, adding, susbtracting, calculating averages, percentages, for instance. But I use them every day, and these were the things people in class used to say, “I’m never going to use this, I’ll just use a calculator”. Well, no, not always, and secondly, you still have to know what you’re doing with a calculator! I’m surprised sometimes by the number of people I know who aren’t sure how to calculate percentages, for example, even on a calculator, if it doesn’t have a ‘%’ button on it.