Question posted by Tammy from Singapore:
Question solved by Model Method: Mr Gogo gave his children Hoho and Haha the same amount of allowance last week. After Hoho had spent $58 and Haha had spent $10, Haha had 4 times as much money left as Hoho. How much allowance did each of them receive last week?
Step 1: It is easier to start with the "After" model and work backwards. First, draw 4 boxes to represent the amount of money Haha had and 1 box to represent the amount of money Hoho had.
Step 2: Next, Draw another box to the right of Haha's model to show the $10 spent and draw another box to the right of Hoho's model to show the $58 spent. Take note that the two models should be equally long as both of them had the same amount of allowance.
Step 3: By comparing the 2 models, we can see that 3 units of the equal unknowns are equal to $58 - $10 = $48.
From the model,
3 units ----------------- $48
1 unit ----------------- $48 / 3 = $16
$16 + $58 = $74
Therefore, each of them had $74 of allowance last week.