a 4-meter-long rope is folded in half and then folded in half, each length is 1 meter.
1. A 4-decimeter-long rope is folded in half and then folded in half, and the length of each rope is 1 decimeter. After folding the 4-meter-long rope in half, it became two sections; After folding in half again, it will be changed from two sections to four sections, so the length of each section of rope is 1 decimeter. Because a rope is folded in half twice and divided into four small ropes, each rope is 4/4=1 decimeter long.
second, for the problem of rope folding in half, the core point is to calculate how many sections the rope is divided into on average after each folding. Folding in half for the first time is relatively easy to calculate, and the average score is divided into 2 segments; The second folding is equivalent to having two ropes folded in half, so it is 2*2=4, which is divided into 4 segments on average; The third folding is equivalent to folding four pieces of rope in half, so the original rope is divided into eight pieces on average, that is, 2*2*2=8.
third, it is not difficult to find from the above that there is a certain relationship between the number of folds and the average number of segments. Assuming that the number of folds is n and the average number of segments is m, there is m = 2 n (n is greater than or equal to 1). This problem belongs to a simple application problem of fractional multiplication. The key is to determine unit 1 and solve it according to the basic quantitative relationship.
the numerator of a fraction is multiplied by the numerator, and the denominator is multiplied by the denominator. If it can be reduced, it must be reduced first, and the numerator cannot be multiplied by the denominator.
Use of rope
1. Mountaineering and hiking: Rope is one of the essential tools in mountaineering and hiking. It can be used for rock climbing, crossing rivers or binding luggage. Different uses require different rope types, such as static rope, dynamic rope, anti-pulling rope and so on.
2. Navigation and fishing: Rope also plays an important role in navigation and fishing. In navigation, ropes can be used for mooring ropes, anchor ropes, towing ropes, and fixing equipment on board. In fishing, rope is used for trawl, fishing rod, lead at the bottom of the net and other tools.
3. medical treatment and rescue: ropes are also widely used in medical treatment and rescue, such as stretchers, suspenders and cable cars. It can help medical and rescue workers to carry out rescue operations in many complex environments.