Think Mentals 2 Answers Online
Perform the calculation: 43 × 17 = (40 + 3) × (20 - 3) = 40 × 20 - 40 × 3 + 3 × 20 - 3 × 3 = 800 - 120 + 60 - 9 = 731
Estimate the answer: Same as above
Visualize the numbers: Imagine a rectangle with sides 40 and 20, and add 3 and -3 to account for 43 and -7 to account for 17. think mentals 2 answers