What does logarithm mean?
Word: Logarithm
Part of Speech: Noun
Meaning: Logarithm means the power to which a base number must be raised to give a particular number. Since 10 x 10 = 100, the logarithm of 100 to base 10 is 2.
Synonyms: log
How do you spell logarithm?
Syllables: log - a - rithm
Tricky part: No vowel is written between the th and the final m, although the ear seems to hear one.
Watch out for: logarithem, logarithum
Memory tip: Keep logarithm in rhythm: the two words finish with exactly the same three consonants.
Logarithm in a sentence
Example 1: Our maths teacher showed us how to find a logarithm on a scientific calculator.
Example 2: Sound levels in decibels are worked out with a logarithm.
Example 3: Astronomers once relied on the logarithm to shorten their long sums.
Fun Fact
The Scottish mathematician John Napier made up the word from Greek words for ratio and number, and published his tables in 1614. It holds exactly the same letters as algorithm.
Practise the CREST Way
Word Cookie
Insert the correct pair of letters to form a word:
log_r_thm
a) a, i
b) e, i
c) a, y
d) o, i
Show answer
a) a, i. The second gap takes an i; rhythm's y has no place in this word.
Word Cookie
One letter in this word is not needed. Find it:
loggarithm
a) g
b) r
c) o
d) i
Show answer
a) g. The first beat has just one g.
Word Makeup
Only one of these words can take the ending ic to make a real word. Choose it:
ic
a) logarithm
b) decimal
c) percentage
d) fraction
Show answer
a) logarithm. Logarithmic is the adjective from this word; the other three have no form in ic.
Spell-o-Spell
Only one word in the list is spelt correctly. Choose its meaning:
1. hypotinuse 2. cofficient 3. exponant 4. logarithm
a) the number written in front of a letter in algebra
b) the longest side of a right-angled triangle
c) a number that lets you multiply by adding instead
d) the small raised number that shows a power
Show answer
c) a number that lets you multiply by adding instead. Exponent has ent, coefficient keeps its oe, and hypotenuse has an e after the t.
Multiple Choice Questions
1. What is the logarithm of 1000 to base 10?
a) 100
b) 30
c) 3
d) 10
Show answer
c) 3
2. Before pocket calculators, which tool was built on the idea behind this word?
a) the set square
b) the slide rule
c) the abacus
d) the compass
Show answer
b) the slide rule
