Let's continue working on comparison problems with numbers and variables (letters). In s­ome problems, we have enough information to solve for the variables.

A comparison problem might have more than one se­ntence. Look at this example:

R equals 18 more than J. J equals 77. What number does R equal?

The best way to approach this problem is to solve one sentence at a time. Let's look at the first sentence: R equals 18 more than J. We already have enough information to figure out the number family for this problem. Whenever a number comes before the word "more" or "less," it equals a lesser (smaller) number. So 18 equals a lesser number here. What about the variables? Well, R equals more than J, so R equals the greatest (largest) number, and J equals a lesser number. Here is our number family: 18 and J equal the lesser numbers, and R equals the greatest number.

Now let's look at the second sentence. It tells us that J equals 77. So we'll cross out J and write the number 77. Our lesser numbers now equal 18 and 77.

There's only one step left. The last sentence asks, "What number does R equal?" We now have enough information to solve the problem. To get the greatest number, R, we add the two lesser numbers; 18 plus 77 equals 95. So R equals 95.