Money Problems

Question 1

Tommy has $10 pocket money a week. On Friday he decides to spend it by going to the sweet store. He buys one Crunchie for $2.50, one Trumpet for $2.80 and a packet of gummy bears for $1.50.

1. How much money has he spent?

2. How much money does he have left over?

Question 2

Mary has a $5 note. She exchanged it with her brother Sam for some coins. 

Could she have exchanged it for 6 coins?

What is the largest number of coins that Sam could have given Mary?