suilin needed 7 dollars 13 cents to buy a book. in her wallet,she found 3 dollar bill , 4 dimes ,and 14 pennies. how much more money do suilin need to buy the book
well lets subtract. but in order to subtract we have to know the total amount of cents she has. so 10 cents in 1 dime. 10×4 or 10+10+10+10 they both equal 40 cents. so add that to the 14 and you have 54 cents. so subtract 7 dollars and 13 cents with 4 dollars and and 54 cents. 7. 13- 4. 54= 2. 59 that means she needs 2 dollars and 59 cents in order to get her book. :)