Find the value of each expression mentally.

1. Here are two algorithms for finding the value of .

   

   

   multiply. 7 hundred 13 times 3. 6 rows. First row: 7 hundred 13. Second row: multiplication symbol, 3. Horizontal line. Third row: 9. Fourth row: 30. Fifth row: plus 2 thousand 1 hundred. Horizontal line. Sixth row: 2 thousand 1 hundred 39.

   Discuss with your partner:

   1. How are these algorithms alike? How are they different?
   2. How do you think Kiran found the product 2,139?

2. Find the value of each product.

1. Analyze the two algorithms used to find the value of .

   

   

   multiply. 2 hundred 23 times 4. 6 rows. First row: 2 hundred 23. Second row: multiplication symbol, 4. Horizontal line. Third row: 12. Fourth row: eighty. Fifth row: plus 8 hundred. Horizontal line. Sixth row: 8 hundred ninety 2.

   1. How are these algorithms alike? How are they different?
   2. Where is the 12 in Kiran's algorithm?
2. 1. Try using Kiran's algorithm to find the value of .
   2. Check your work using a different method.