8 in 2.408 is closer to 10, so you round 2.408 to 2.41
Answer:
486
Step-by-step explanation:
for the 2nd term, add 5 to -9
for the 3rd, add 5 × 2 to -9
for the 4th, add 5 × 3 to -9
:
for the 100th, add 5 × (100 - 1) to -9
=> 5 × 99 + (-9)
=> 486
Answer:
The best estimate for 43x78 is 40x80
Step-by-step explanation:
43 rounded to the nearest ten is 40.
78 rounded to the nearest ten is 80.
The answer to 40x80 is 3200