约翰逊先生有一块种植蒲公英的田地。平均每平方米生长 70 株蒲公英。每株植物平均有 10 朵花。每朵花平均产生 150 粒种子。估计这些植物总共将产生 130 000 000 粒种子。

1. Calculate the number of packets by division.

Number of packets
$= \frac{130\,000\,000}{55}$
$= 2\,363\,636.36\ldots$

2. Write the answer in standard form to a sensible accuracy.

$2\,363\,636.36\ldots = 2.363636\ldots \times 10^6$
To 3 significant figures,
$2.363636\ldots \times 10^6 \approx 2.36 \times 10^6$

1. Find the average number of seeds produced per square metre.

For each square metre:

$70$ plants grow.

Each plant has $10$ flowers, and each flower produces $150$ seeds.

$70 \times 10 \times 150 = 105000$

So $105000$ seeds are produced per square metre.

2. Divide the total number of seeds by the number of seeds per square metre.

$\text{Area of plot}=\frac{130000000}{105000}$

$=1238.095\ldots$

To the nearest square metre,

$\text{Area}=1238\text{ m}^2$