we know that
There are many strategies that we could use. We will use compatible numbers for this problem.
step 1
Multiply the divisor and dividend by 10.
48.6*10=486
0.7*10=7
step 2
The number 486 is close to 490
The numbers 7 and 490 are compatible since they make it easy to do mental arithmetic.
step 3
estimate the quotient
quotient=.dividend/divisor
quotient=490/7------> 70
the answer is
the best expression to use is (490/7)