Q: A sliding caliper is basically a ruler with two pincers attached to it. One pincer is stationary at the end of the ruler, and the other slides so you can measure the distance between the pincers. You can use a caliper intended for medical purposes, or even one made for home improvement or automotive uses. You can take the measurement with a caliper yourself, but it's much easier to get an accurate measurement if someone else does it for you. If you don't have a caliper, you'll have to improvise and use your thumb and forefinger and a ruler to take a less accurate measurement. Slide the pincers apart so they are comfortably wider than the elbow. Hold the caliper up to the elbow so that the stationary pincer and the base of the caliper are snug against the elbow. Slide the movable pincer until it is also snug against the elbow. The pincers should be pointed straight up at the same angle as the lower arm. The pincers should be firmly against the bones of your elbow, but you don't need to squeeze them tightly. You should be able to slide the caliper straight down off the elbow without loosening the pincers. If you only need a relatively accurate elbow measurement, pinch the thumb and forefinger of your non-dominant hand against either side of your dominant elbow. Your thumb and forefinger should be pointed upward at the same angle as your lower arm, and you should try to measure at the elbow's widest point. Pinch firmly enough that you feel the bone in your elbow, but don't squeeze your thumb and forefinger with full pressure. Unlike using calipers, it's just as easy for you to do this less-accurate measurement yourself as it is to have a friend do it. Try your best to keep your thumb and forefinger in the same position, and slide them off of your elbow. Hold a ruler between them, or rest them on a ruler placed on a desktop. Record the measurement as accurately as you can. It's impossible for you to keep your thumb and forefinger in the exact same position the whole time, so this measurement can never be reliably accurate with any real precision. You might want to repeat the measurement a few times and use the average.
A: Have a friend use a sliding caliper to measure, if possible. Measure the widest part of the elbow with the caliper. Use your other thumb and forefinger as a makeshift caliper, if needed. Measure the width between your thumb and forefinger with a ruler.

Q: Maybe you picture a traditional British tea party, with fancy sandwiches and doilies. Or maybe the guests want to dress up as princesses, pretend to be fairies, or decorate a room as though it were winter, or underwater. Finding out what the guests are excited about will help you make it more fun for them. Keep in mind that some themes require more work than others. If you're looking for a quick and simple theme, pick a single color and decorate a room or table with flowers, objects, napkins, and dishes in that color from around the house. If the weather is sunny, you could host a tea party in your garden or take a picnic to a nearby park. Throwing a tea party indoors is also fun, though, and gives you the option of hanging up decorations. Give cards to your friends inviting them to your tea party, but make sure to check with everyone in your house first to see how many people you can bring over. Remember to let your friends and family know what day and time the tea party are. You can plan a tea party weeks in advance, or throw one spontaneously with your brothers and sisters. Whatever makes you happy! Ask your friends to bring their favorite doll or stuffed animal. Tea parties don't have to be all-girl or all-boy. Invite anyone who makes you happy. For some people, the best part of a tea party is getting to dress up. If you don't have any fancy clothes or costumes to put on, try making your own silly costumes by asking family members if you can put on their hat, makeup, or scarves. It's a good idea to keep a few extra objects like this around for guests who show up without a costume. Princess costumes can be as simple as the kid's favorite dress and a paper crown. If you are willing to spend extra time on costumes, sew them from patterns, use face paint, or track down pre-made costumes online or at Halloween shops. If you and the other kids and parents involved want to throw a super special tea party, have each kid pick a character from their favorite book, or from a single popular book such as Alice in Wonderland or Harry Potter. A fancy tea party might have tea pots, teacups, and saucers, but you can host a tea party using any dishes. Just make sure there's at least one plate and one cup for each person. Silverware is optional if you are only going to be serving finger food, such as sandwiches and cookies. If you are holding a tea party indoors, you might want to hang up colorful cloths or flags, or put stuffed animals and art projects around the room. Flowers at the center of the table or picnic blanket can give people something pretty to look at. Hold a faerie tea party in a garden or park, using toy mushrooms, flowers, and moss covered rocks to make a faerie circle. Create a winter wonderland theme with paper snowflakes, hanging white cloths, and hot cocoa (or iced tea if you are holding it in summer). Many kids don't like black tea, or it might make them hyper or make it hard for them to sleep. Fortunately, there are plenty of other teas such as peppermint, lemon, or rooibos (red tea). Since not everyone likes tea, it's a good idea to have lemonade, juice, or milk around to serve as well. Ask an adult to help you make the tea if you aren't supposed to boil water on your own. If your guests don't like tea or you don't want to serve hot drinks, put juice in a teapot instead. For a real tea party feel, make sandwiches out of cream cheese, cucumber, or just butter. Have an adult help you cut them into triangles or small pieces, and arrange them on a plate in a pyramid or other shapes. Use a cookie cutter on the sandwich to create sandwiches in different shapes. This works best with squishy bread that holds together well. American cookies or British biscuits make great finger food for a tea party, as do scones or small cakes. You can buy these from a store or make them yourself with adult supervision. Most tea parties don't serve a full meal, just some drinks and snacks. But if your guests will be staying during lunchtime or dinnertime, you might need to feed them pasta or some other bigger meal. Be sure to let your guests know whether or not you'll be feeding them a full meal or whether they should eat at home before coming. Decide what games and activities you want to plan for the party, and gather any items you need before the party starts. You could play games, make art projects, or just have fun pretending to be English royalty. For example, make a faerie house or garden, decorate with homemade pinwheels, or make a fun dessert with your guests.
A:
Choose a theme. Decide on a location. Invite guests. Dress up. Make sure you have enough plates and cups. Decorate the table or room. Find some drinks to serve. Make sandwiches. Have dessert ready too. Consider whether your guests need more food. Figure out what to do for entertainment.