Use the Associative Propety:
1/ Diego bought 7 sheets of stamps. Each sheet had 3 stamps per row. How many stamps did Diego buy in all ?
The answer:
7*(3*3)=
7*9=63
2/ Four children have the same birthday . At their party ,each child had 1 cake there were 8 candles on each cake. How many candles were there in all?
The answer:
4*(1*8)=
4*8=32