Bar model<span>. Visual representation of a number using unit cubes, lines (of 10 cubes), sheets (of 100 cubes) and boxes (of 1000 cubes). Used in pictorial approach to solving addition and subtraction problems.</span>
Answer:found it
Step-by-step explanation:
398643-457854=4574
Nowhere there was no additional dollar. The $30 minus the $2 the waiter kept and minus the $3 he gave back. $3+$2=$5, which would be $30-$5=$25
The values of a and b equals 10