4500 ÷ 0.45% = 100000 (species) roots are obtained by "finding the quantity of unit one, using the quantity corresponding to the fraction (4500 species) ÷ fraction (0.45%) = the quantity of unit one". (Insect species is the first unit)
The species of insects is 1000000.
Let the species of insects be X, and the roots have an equal relationship test: insect species × 0.45% = 1000000.
0.45%X = 4500
X = 4500 ÷ 0.45%
X = 1000000
The species of insects is 1000000.
2. A bundle of wires used 35%, which is exactly 63 meters. What is the original length of this bundle of wires?
The root fixture is made by "finding the quantity of unit one, and using the corresponding fractional quantity (63m) ÷ fractional quantity (35%) = unit one" (the original length of this bundle of wires is unit one).
63 ÷ 35% = 180 (m)
Answer: The original length of this bundle of wires is180m.
Let the original length of this bundle of wires be x meters. Equivalence test: the original length of this bundle of wires × 35% =180m.
35%X = 63
X = 63 ÷35%
X = 180
Answer: The original length of this bundle of wires is180m.