Taking a math test can be pretty stressful. Even if you know the material, you can still get the problem wrong. Knowing how to go through your math test and check your work can save you from handing in a test full of mistakes that can be avoided. {#blank#}1{#/blank#}

Write it out

    You can also check a math problem by writing everything out on paper. {#blank#}2{#/blank#} Writing out math problems reduces your chances of missing anything to the lowest possible level, which is a common cause of incorrect answers.

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    Make sure your answers work by doing the opposite procedure of what your problem calls for, including the answer you got the first time around. In other words, you would use the opposite of this addition problem—subtraction (减法)—to determine whether or not your answer is the correct one.

Plugging in

    You may find that a variable isn't good enough or have a problem where you have to solve for a variable (变量). {#blank#}4{#/blank#} This is the only real way to assure yourself that the answer you've found is correct.

Check for a reasonable answer

    {#blank#}5{#/blank#} For example, if you get an answer in the millions and you know it should be in the thousands, you've likely misplaced a point. Go back through the work on your paper to make sure all of your formulas and calculations are correct. If everything looks okay, do the problem again and compare the result of the second try to what you've got on the first try.

    Earlier this year, the social media website Facebook announced that it would work with several news organizations — including The New York Times, The Guardian, and the BBC — to place news stories directly into users' personal Facebook webpage.  Stories published using Facebook Instant will load more quickly and keep the style of the original publisher, who will keep all the advertising income the stories earn — at least for now. The deal shows how important social media has become to news organizations, and is a clear sign of how the world of news is changing — and has been for a while.

    When Google News began in 2002, many saw it as the death of the newspaper. It had no human editor. Instead Google used, and still uses, a secret computer program that selects and displays news stories according to the reader's personal interests. More recently, Associated Press and Yahoo! have been publishing computer-written articles. Both use special software to automatically produce stories about company financial results and sports reports — areas where the quality of writing is felt to be of secondary importance to the accuracy of the data.

    Should we be worried about such developments? I think we should. One concern is that facebook, Google and other social media websites see journalism as a sideline, a way of putting people in front of advertisements. It isn't their primary function — so if it stops making them lots of money, they're likely to stop doing it.

    There's also a concern that computer-written articles are not actually journalism at all, because what a human news team produces is actually quite complex. A well-written news story puts information in context, offers a voice to each side of an argument and brings the public new knowledge.

    Though economics and speed of delivery mean readers will probably choose a computer-written story over a carefully shaped article — at least for daily news — I don't think the computers will be writing any in-depth articles for a while yet.

    Parents who help their children with homework may actually be bringing down their school grades. Other forms of parental involvement, including volunteering at school and observing a child's class, also fail to help, according to the most recent study on the topic.

    The findings challenge a key principle of modern parenting where schools expect them to act as partners in their children's education. Previous generations concentrated on getting children to school on time, fed, dressed and ready to learn.

    Keith Robinson, the author of the study, said, "I really don't know if the public is ready for this but there are some ways parents can be involved in their kids' education that leads to declines in their academic performance. One of the things that was consistently negative was their parents' help with homework." Robinson suggested that may be because parents themselves struggle to understand the tasks."They may either not remember the material their kids are studying now, or in some cases never learnt it themselves, but they're still offering advice."

    Robinson assessed parental involvement performance and found one of the most damaging things a parent could do was to punish their children for poor marks. In general, about 20% of parental involvement was positive, about 45% negative and the rest statistically insignificant.

    Common sense suggests it was a good thing for parents to get involved because "children with good academic success do have involved parents", admitted Robinson. But he argued that this did not prove parental involvement was the root cause of that success. "A big surprise was that Asian-American parents whose kids are doing so well in school hardly involved. They took a more reasonable approach, conveying to their children how success at school could improve their lives."

    The discussion on renewable energy has been going on for at least a decade and people have relied on fossil fuels almost entirely for more than a century. However, the situation when fossil fuels were the most efficient and the cheapest source of energy has been left far in the past. Many countries such as Germany and Sweden have already made significant efforts to fix this situation, employing numerous power plants working on the renewable resources of energy. The most effective among these resources is geothermal（地热的）energy.

    Geothermal energy does not depend on the world's economic and political situation as strongly as fossil fuels do. Besides, extracting（提炼）fossil fuels adds to the price of energy produced from them. Therefore, geothermal energy is much cheaper than traditional ones, saving up to 80% of the costs over fossil fuels.

    Being a renewable resource, geothermal energy produces less waste and pollution than traditional energy sources. In geothermal systems, carbon dioxide makes up about 10% of air produced. Overall, in order to produce the electricity that can be used for one hour, the geothermal systems produce 0.1 pound of carbon dioxide and other harmful gases. For a comparison, a power plant producing from gas produces up to 2 pounds of carbon dioxide into the atmosphere, and those power plants that work on coal（煤）produce an astonishing 3.6 pounds of greenhouse gases.

    Low costs is another reason why using geothermal power plants should be the first choice for many countries. Geothermal heat systems require 25% to 50% less energy for work compared with the traditional systems for heating or cooling. Besides, geothermal equipment is less big: due to the very nature of geothermal energy, geothermal power plants have only a few moving parts, all of which can be easily sheltered inside a relatively small building. What's more, the life span of geothermal equipment is rather long. All these make geothermal power stations easy to build and keep.

    A fourth-grade teacher allowed one of her students to shave her head in the schoolyard, after bullies（仗势欺人者）teased him about his own short buzz cut（短寸头发型）. Tori Nelson got the idea after noticing that Matthew Finney, a shy boy from her homeroom at Winlock Miller Elementary School in Washington state, was standing outside his classroom crying and wearing a winter hat.

    Ms. Nelson could see the back of his neck had been shaved, and since Matthew usually had very thick brown curly hair, she realized that he'd had a haircut over the weekend. She asked him what was wrong, and he said he'd gotten a buzz cut for the summer. But this morning, a fifth grader on the bus made fun of him, and he didn't want to come to class and get teased by other kids. Ms Nelson tried to convince Matthew to come inside, but since school rules prohibit kids from wearing hats indoors he refused – explaining that he was afraid of showing his haircut to the other children in case they also made fun of him.

    Finally I said: "If you take off your hat and come to class, I'll let you give me a buzz cut, too," 'Ms Nelson told Yahoo Parenting. I figured it's just hair, and mine is already short anyway. I might as well get it shorter in time for the warm weather.'

    Matthew excitedly took her up on the offer, and Ms Nelson and another teacher gathered all the fourth graders together during break time. A school employee brought in scissors, which Matthew used to the cheers of his classmates, excitedly watching as his teacher's hair fell away onto the ground in the schoolyard.

    'It was a lot of fun for the kids, and it helped Matthew feel better about himself,' said Ms Nelson.' You have to do what it takes to reach children. Teaching isn't just about reading and writing, it's about self-esteem and accepting differences.'

    The "Boomerang Kids" — young adults who leave to go to college, get married or just show off their independence — are moving back in with mom and dad. Boomerang Kids can be a mixed blessing for parents, both emotionally and financially.

    Especially during hard economic times, adult children head for home. According to a survey, about 40 percent of 2017 graduates still live with their parents. Moreover, 42 percent of the 2015 graduates surveyed said they are still living at home.

    The reasons are many, the first being economics. While the recession(衰退) has touched Americans of all ages, it has been very hard for young adults. This has sent many kids back home. Plus, there is the matter of debt, especially college loans. For many recent graduates, it makes smart economic sense to move back in with their parents where life is comfortable and rent is either low or nonexistent. Then, of course, some return for personal reasons, such as recovering from a divorce or an illness.

    Parents are often glad to help out, both emotionally and financially. As a result, the arrangement often works to everyone's satisfaction. However, there are risks, especially for the parents. These include not only family tension and misunderstandings, but also money. The return to the family can become a financial burden that can affect the parents' plans and their financial future, especially their retirement, as they try to do too much for their children.