Adding fractions that share the same denominator by adding the numerators and keeping the denominator.
If you have 52β of a pie and get 51β more, you now have 53ββsame size pieces, just count them up.
Showing a random 20 of 50 problems.
Example 1
medium
113β+11?β=1110β. Find the missing numerator.The result bar must reach 10 out of 11. How many more pieces (shown as ?) must the middle bar have?
Example 2
challenge
For positive integer n, simplify n1β+n2β+n3β+β―+nnβ in closed form.
Example 3
easy
A bowl has 104β kg of rice. You add 103β kg more. How much rice is in the bowl?
Example 4
medium
Add 92β+94β+91β.
Example 5
medium
Express 204β+206β in lowest terms.
Example 6
easy
Add 61β+64β.One sixth plus four sixths fills five of the six equal parts in the result bar.
Example 7
challenge
Express 81β+81β+81β+81β as a single fraction and as a decimal.
Example 8
medium
Find the missing numerator: 134β+13β‘β=1311β.
Example 9
medium
Add 85β+87β and write the result as a mixed number.
Example 10
medium
Two ribbons are 83β m and 84β m. What is their total length?Each bar represents one metre split into 8 equal sections. Joining the two ribbons fills 7 of those sections.
Example 11
medium
Add 283β+187β.
Example 12
hard
Bag A has 125β kg of flour, bag B has 127β kg, bag C has 1211β kg. Total mass?
Example 13
easy
Worked example: add 62β+63β and show why the denominator does not change.
Example 14
medium
Compute 2011β+2013β and write as a mixed number.
Example 15
medium
Add 154β+156β and simplify.Ten of 15 parts shaded in the sum bar reduces to 2/3 after dividing numerator and denominator by 5.
Example 16
hard
Find all positive integers nβ€10 such that 12nβ+12nβ simplifies to a unit fraction k1β.
Example 17
easy
True or false: 103β+102β=205β.
Example 18
easy
Add 41β+41β.Two fourths fill exactly half the bar, showing why 2/4 simplifies to 1/2.
Example 19
challenge
If 12aβ+12bβ=129β and a=2b, find a and b.
Example 20
easy
A jug contains 72β litre of water. You pour in another 73β litre. How much water is in the jug?The jug starts with 2 seventh-parts and gains 3 more, for a total of 5 out of 7.