Measurement conversions
Length, weight, capacity, and time — metric and customary — on one page, ending with the bit children actually get wrong: whether to multiply or divide.
Reference chart
Measurement conversions
Length · metric
- 10 millimeters = 1 centimeter
- 100 centimeters = 1 meter
- 1,000 meters = 1 kilometer
Mass and capacity · metric
- 1,000 grams = 1 kilogram
- 1,000 milliliters = 1 liter
Length · customary
- 12 inches = 1 foot
- 3 feet = 1 yard
- 5,280 feet = 1 mile
Weight and capacity · customary
- 16 ounces = 1 pound
- 8 fluid ounces = 1 cup
- 2 cups = 1 pint
- 2 pints = 1 quart
- 4 quarts = 1 gallon
Time
- 60 seconds = 1 minute
- 60 minutes = 1 hour
- 24 hours = 1 day
- 7 days = 1 week
- 12 months = 1 year
Which way round
- Moving to a smaller unit makes more of them, so multiply.3 m = 3 × 100 = 300 cm
- Moving to a bigger unit makes fewer, so divide.4,000 g = 4,000 ÷ 1,000 = 4 kg
What's on this chart
The metric side of this chart is really the place value chart wearing different labels. Ten, a hundred, a thousand: the same jumps, so a child who can move a number between centimeters and meters is doing exactly what they do when they multiply by a hundred. Saying that out loud tends to make the whole metric system feel like one idea instead of nine facts.
Why this chart helps
The customary units have no such pattern, and it is worth telling a child so. Twelve inches in a foot, three feet in a yard, 5,280 feet in a mile — these are not derivable from anything, they are historical accidents that simply have to be known. A child who thinks they are missing a rule will keep hunting for one; a child who knows there is no rule just learns the numbers.
More printable charts
- Rounding rules
Print Find the place, look at the digit beside it, then decide. - Mental math tricks
Print Swap the hard number for an easy one before you start calculating. - Divisibility rules
Print Run one quick test in their head instead of starting a division. - Fraction rules
Print Check a fraction answer against the rule before doing the arithmetic. - Order of operations
Print Work down the ranks, taking each one left to right before the next. - Positive and negative numbers
Print Check which operation you are doing before deciding the answer's sign. - Laws of exponents
Print Find the operation you have, and the example shows where the rule comes from. - Scientific notation
Print Move the decimal point to a number between 1 and 10, then count the places as the power.