King Henry (all metric)
kilohectodeca
metre / litre / gram
decicentimilli
Every step left or right is x10 or divide by 10.
Mnemonic: King Henry Died By Drinking Chocolate Milk.
Length
km = 1000 mm = 100 cmcm = 10 mm
Biggest to smallest: km → m → cm → mm.
Going to a BIGGER unit? The number gets SMALLER (divide).
Mass
t = 1000 kgkg = 1000 gg = 1000 mg
t = tonne, kg = kilogram, g = gram, mg = milligram.
1 kg ≈ a bag of sugar. 1000 g in it.
Capacity
kL = 1000 LL = 1000 mL1 cm³ = 1 mL
kL = kilolitre, L = litre, mL = millilitre.
A 1 cm cube holds exactly 1 mL. So 1000 cm³ = 1 L.
Area is SQUARE
1 m² = 10 000 cm²1 ha = 10 000 m²1 km² = 1 000 000 m²
Sides are x100, so the AREA is x100 x 100 = x10 000.
Square = two sides, so count the zeros TWICE.
Volume is CUBIC
1 m³ = 1 000 000 cm³1 L = 1000 cm³1 m³ = 1000 L
Sides are x100, so the VOLUME is x100 x 100 x 100 = x1 000 000.
Cube = three sides, so count the zeros THREE times.
Tip: pick a category up top, or leave it on All to mix everything.