Amedium sized apple has 70 calories. this is 10 calories less than 1/4 of the calories in an old chocolate bar. we need to find out how many calories are in the bar? what could be a model for the first step?

Define x:

Let x be the calories of the old chocolate bar.
Apple = 1/4 x - 10        ←First Step : Define apple with reference to the choc


Information Given:

Apple = 70 Calories 


Find x:

1/4 x - 10 = 70              
1/4 x = 80
x   = 320 calories


The old chocolate bar is 320 calories.