Final answer:
The best estimate of (13)(126) is 1300.
Step-by-step explanation:
To estimate (13)(126), we can round each number to the nearest ten and then multiply. Round 13 to 10 and round 126 to 130. Now multiply 10 by 130:
10 x 130 = 1300
So, the best estimate of (13)(126) is 1300.