Exercise 7 Page 16

To divide 153 by 18, we first make an estimation. Since 153 and 18 are close to 150 and 20, these numbers seem good to use for our estimation. 150 ÷ 20 = 7.5

The quotient of 153 and 18 is about 7.5, so the first digit of the quotient will be in the ones place. We calculate the actual quotient by following four steps.

1. Divide
2. Multiply
3. Subtract
4. Compare

After that, the remaining number should be less than the divisor.

Finally, we have that 153÷ 18 is 8 R9. We know that the answer is reasonable because 8 is close to our estimate.