Bar Model Trial and Error Solution to Two Variable Problem

Author:
Lew W.S.
Cheryl has more money than Albert. If Cheryl gives $40 to Albert, they will have the same amount. If Albert gives $80 to Cheryl, Cheryl will then have four times as much as Albert. How much money does each of them have?

Breakdown the problem into 2 parts (conditions)

Condition 1 : If Cheryl gives $40 to Albert, they will have the same amount. Condition 2 : If Albert gives $80 to Cheryl, Cheryl will then have four times as much as Albert. Use the specially constructed bar model diagram below to find the right amount that fits the above requirements. Click on the checkbox for condition 1. You will see a slider for changing Cheryl's amount of money. Adjust her amount until condition 1 is met. Click on the checkbox for condition 2. You will see a slider for changing Cheryl's amount of money. Adjust her amount until condition 2 is met. Now you should make sure that the amount that Cheryl and Albert each have are the same set of values but satisfy both condition 1 and 2