Subtracting fractions with different denominators by first rewriting them with a common denominator, then subtracting numerators.
To find 43−31, convert to twelfths: 129−124=125. Same idea as addition, just subtract.
Showing a random 20 of 50 problems.
Example 1
easy
Subtract 125−41.Convert 1/4 to 3/12 to subtract from 5/12
Example 2
challenge
If 6a−81=245, find the whole number a.
Example 3
easy
Subtract 53−101.Convert 3/5 to 6/10 to match the denominator
Example 4
medium
Subtract 32−92.
Example 5
easy
Subtract 43−21.See that 1/2 equals 2/4 to find what remains
Example 6
challenge
Order from largest to smallest the differences 21−31, 31−41, 41−51.
Example 7
medium
Subtract 149−72.
Example 8
medium
A runner completed 87 of a race, then stopped. If the race is 1 km long, what fraction of the race is left? If another runner has already finished 52 of the remaining distance, how much of the total race has that runner covered?
Example 9
medium
1211−6?=41. Find the missing numerator.
Example 10
easy
Subtract 87−41.Convert 1/4 to 2/8, then subtract from 7/8
Example 11
easy
Subtract 21−31.Both halves and thirds convert to sixths
Example 12
medium
Subtract 1211−43 and simplify.
Example 13
medium
A board is 87 m. You cut off 31 m. How much remains?
Example 14
easy
Subtract 43−81.Fourths expand to eighths to enable subtraction
Example 15
medium
Subtract 65−92.
Example 16
challenge
Compute 21−31+41−51.
Example 17
medium
Subtract 65−41.LCM of 6 and 4 is 12; convert both fractions