Question

How do i compare numerical expressions without calculating them

Answer 1

To do that you need to notice the difference between the given expressions. Take the following case as an example: 10*40 and 20*40. The second expression is double than the first one because 20 is double than 10.

Another example:

20*2 and 10*2 + 10*2

These expressions are equal because 20 can be expressed as 10 + 10; then, distributing the multiplication gives the second expression.

Answer 2

write simple expressions that record calculations with numbers and interpret numerical expressions without evaluating them. For example, express the calculation
"add 8and 7 then multiply by 2". as 2×(8+7). Recognize that 3×(18932+921) is three times as large as 18932+921 without having to calculate the indicated sun and product.
Good luck hope I helped!!:-)