Grade 8 Ratios & Proportions Missing Number
Grade 8 ratios and proportions missing number sheet: 24 problems on solving proportions, equivalent ratios.
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Three different problem sets — same skill, same layout, fresh numbers.
Preview — Set A
Find the number that belongs in each blank.
- 1.Solve: 4/1 = x/5
- 2.7:1 = ___:8
- 3.Solve: 2/x = 10/45
- 4.8:5 = ___:20
- 5.Solve: 5/1 = 25/x
- 6.1:9 = 8:___
- 7.Solve: 5/x = 45/9
- 8.9:7 = 18:___
- 9.Solve: x/3 = 44/12
- 10.1:8 = ___:32
- 11.Solve: 1/3 = 4/x
- 12.4:4 = 8:___
- 13.Solve: 4/x = 8/20
- 14.6:2 = ___:4
- 15.Solve: 3/11 = 24/x
- 16.4:2 = 12:___
- 17.Solve: 12/x = 36/21
- 18.8:6 = 56:___
- 19.Solve: 10/11 = x/44
- 20.2:7 = 14:___
- 21.Solve: 5/3 = x/21
- 22.4:6 = ___:24
- 23.Solve: x/9 = 24/36
- 24.7:7 = ___:49
What this worksheet covers
There are 24 ratios and proportions problems here — one page to work, one page of answers to check against — and Sets B and C repeat the layout with different numbers. Within that, some values are written as fractions rather than whole numbers and the blank moves between positions from problem to problem, so no single procedure clears the page. Problems 9 and 17, for instance, are "Solve: x/3 = 44/12" and "Solve: 12/x = 36/21". The sheet sits inside Common Core 7.RP.2, in the grade 7 Ratios & Proportional Relationships strand.
Skills practiced
At grade 8, ratios and proportions is about proportional relationships and slope, solving proportions, similar figures and scale factors, and this sheet takes one slice of that. The skills on the page: solving proportions and equivalent ratios. To finish it, a student has to work in fractional units and give the answer in lowest terms and reason backwards from a result to a missing part. 23 different answers appear across the 24 problems, so a student cannot copy one result down the page.
About the missing number format
Each of the 24 problems has a blank, and the blank is not always at the end: problem 9, "Solve: x/3 = 44/12" puts it where the student has to reason backwards. A missing term in a ratio or proportion is the format's natural home; the whole topic is finding the missing term.
Set A, Set B and Set C
All three sets are produced by the site's deterministic generator from a fixed seed, so they are the same every time the site is built and the answer keys are exact. Where Set A's problem 13 is "Solve: 4/x = 8/20", Set B's is "Solve: x/9 = 64/72".
How to use this worksheet
Work it without a calculator. Every one of the 24 ratios and proportions problems is designed to be done by hand, and reaching for a calculator at grade 8 skips exactly the reasoning being built. Date the missing number before filing it. Set C from six weeks later is the cheapest evidence you have that the ratios and proportions stuck.
One mistake to watch for
A proportion is cross-multiplied with the wrong pairs. Watch problem 3 of this missing number — "Solve: 2/x = 10/45" — for this one.
The setup was written with mismatched units across the equals sign.
Label every term with its unit before solving; the same unit must be on top on both sides.
Other grade 8 ratios and proportions formats
The same skill in the other formats available at this grade.
A step either side
The same format one grade down and one grade up — the easier sheet is often the faster fix when this one is not landing.
- Grade 7 Ratios & Proportions Missing Number — grade 7, 24 problems
Missing Number sheets in other grade 8 topics
No paywall and no account — download any set of this grade 8 ratios and proportions missing number, and the answers for all 24 problems are in the matching key.