The length of a cricket bat is 0.87 m. Convert this to cm.

Hint: To solve the problem, we need to know about the basics of conversion of units. In this case, one needs to be especially acquainted with conversion in reference to units of distance.

Before, starting first let us know about meters and centimetres in detail. Meters and centimetres are the units of measurement of the distance (there are many such units of measurement of distance, but for now we will consider only these two). Now, although all these units are used to measure distance, these two differ in the quantity of distance they denote. Generally, for larger distances, we use metre while for smaller distances, we use to denote the distance in cm. For even larger distances than metre, we use kilometre and for smaller distances than centimetre, we use millimetre. Now coming back to solving the question, we need to remember that-
1 m =100 cm -- (1)

Complete step-by-step answer:
Now, we can use the unitary method to solve the given problem in hand. Basically, the unitary method is a technique for solving a problem by first finding the value of a single unit, and then finding the necessary value by multiplying the single unit value. In essence, this method is used to find the value of a unit from the value of a multiple, and hence the value of a multiple. To explain this definition,

Let’s say, 2 bags cost 50 rupees and suppose we want to know how many bags we can buy from 75 rupees. What we do is, we see how many bags can be bought for 1 rupee. Then we multiply that by 75. Thus,

For 50 rupees, we have 2 bags

For 1 rupee, we have $\dfrac{1}{25}$bags

For 75 rupees, we have $\dfrac{75}{25}$=3 bags

We use a similar methodology to solve the given problem in hand.

Now, from (1),

0.87 m = 0.87$\times $100 = 87 cm

Hence, the correct answer is 87 cm.

Note: When solving questions involving the conversion of units of distance from one unit to another, it is always useful to remember the basic conversion formulas. Further, in applying unitary method, it is only applicable when the quantities are directly related to each other. In case a quantity is directly related to square/cube/inverse or any other operations, the unitary method yields inaccurate results. For example, if x varies as a square of y, we cannot use unitary methods between x and y variables.