Q: I want to support about 10 charities and nonprofits but have a limited budget of $1,000. I’ve been dividing it among those charities, but would I have a bigger impact contributing the full amount to just one?

A: Absolutely, for a number of reasons.

Each charity spends a certain amount to process your donation. The smaller the donation, the more of it is eaten up by these costs. If it costs $5 to process a donation, for example, the costs represent 5% of each $100 donation. If $1,000 went to one charity, just one fee would be incurred and it would represent just 0.5% of the total.

Any donation you give can trigger more appeals from the charity, so you’re potentially incurring 10 times the junk mail.

Wise donors also research charities using services such as GuideStar or Charity Navigator to make sure the bulk of their contributions go to the cause, rather than to executive salaries, fundraising and overhead. Monitoring 10 charities is a lot more work than keeping track of one or two.

You might also consider making monthly contributions, rather than waiting until the end of the year, since that helps charities budget. A direct debit from your checking account is often the best way to set this up, because using a credit card incurs transaction fees that reduce your contribution.

Q: My parents, who are in their 80s, just moved and are about to sell their former home. Their net gain from the sale will be approximately $400,000. I am advocating they put this money in a high-yield savings account as capital preservation is key. I know an individual account is insured by the FDIC for up to $250,000. But if we set it up so they are joint account holders, would the FDIC insurance limit on that one account rise to $500,000?

A: Yes. The FDIC insures up to $250,000 per depositor, per institution and per ownership category. Ownership categories include single accounts, joint accounts, certain retirement accounts such as IRAs, revocable trust accounts and irrevocable trust accounts, among others. Each depositor in a joint savings account is covered up to $250,000, so a couple would have $500,000 of coverage.

Liz Weston, Certified Financial Planner, is a personal finance columnist for NerdWallet. Questions may be sent to her at 3940 Laurel Canyon, No. 238, Studio City, CA 91604, or by using the “Contact” form at asklizweston.com.