Show at least two ways other than using a calculator to find Explain in writing why each makes sense.
Your question doesn't make any sense.
Sorry, the question is show at least two ways other than using a calculator to find 13 x 31. Explain in writing why each makes sense.
Straight multiplication using pencil and paper is one.
What is another way?
1) Estimation: Estimation is a quick and rough way to find an approximate answer without using a calculator. For example, if you need to find the square root of 37, you can estimate by thinking of the closest perfect squares. The perfect squares near 37 are 36 (which is 6^2) and 49 (which is 7^2). Since 37 is closer to 36 than 49, you can estimate that the square root of 37 is closer to 6. Estimation can be useful in situations where you don't need an exact answer, but just a general idea of the magnitude of the solution.
2) Using mathematical properties and relationships: Sometimes, you can use known mathematical properties or relationships to find the answer without a calculator. For example, if you need to find the value of sin(30°), you can use the fact that sin(30°) is equal to 1/2. This is a well-known property of trigonometric functions. Similarly, if you need to multiply two numbers, you can use the distributive property or properties of exponents to simplify the calculation. Using mathematical properties and relationships can save time and effort in solving certain types of problems, especially when the values involved have specific relationships that can be exploited.