MTH1W Number Sense
Grade 9 Unit 1 — practice questions with full solutions
Integers, fractions, decimals, powers, ratios, rates and percent. Almost every later unit leans on these skills, so this is the one to get airtight first.
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- Follow BEDMAS. Powers first: (−2)2 = 4.
- Expression becomes −3 + 5 × 4 − 12 ÷ (−4).
- Multiply and divide, left to right: 5 × 4 = 20 and 12 ÷ (−4) = −3.
- Now: −3 + 20 − (−3) = −3 + 20 + 3.
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- The lowest common denominator of 3, 6 and 4 is 12.
- Rewrite each fraction: 8⁄12 − 10⁄12 + 9⁄12.
- Combine the numerators: 8 − 10 + 9 = 7.
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- In (−2)4 the brackets mean the whole number −2 is the base: (−2)(−2)(−2)(−2) = 16.
- In −24 there are no brackets, so only 2 is the base and the negative sign is applied at the end: −(2 × 2 × 2 × 2) = −16.
- The brackets decide what the base actually is — this is one of the most common places students lose marks.
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- (a) Each small tick is 0.5. P sits half a unit left of −2, so P = −2.5. Q is half a unit right of 0, so Q = 0.5. R sits exactly on 2, so R = 2.
- (b) Distance is always positive — subtract the smaller from the larger: 2 − (−2.5) = 2 + 2.5 = 4.5.
- (c) The midpoint is the average of the two values: (0.5 + 2) ÷ 2 = 2.5 ÷ 2 = 1.25.
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- Find the scale factor: 30 ÷ 12 = 5⁄2.
- Multiply the sugar by that factor: 3⁄4 × 5⁄2 = 15⁄8.
- Convert to a mixed number: 15⁄8 = 1 7⁄8.
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- Convert every value to a decimal so they can be compared fairly.
- 2⁄3 = 0.666… and 5⁄8 = 0.625.
- Now compare: 0.6, 0.625, 0.666…, 0.67.
- Careful with the last two — 0.666… is slightly less than 0.67.
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- A 15% discount means you pay 85% of the price: 85 × 0.85 = $72.25.
- Adding 13% tax means multiplying by 1.13: 72.25 × 1.13 = 81.6425.
- Round to the nearest cent.
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- Count the parts: the grid is 5 columns by 4 rows, so there are 20 equal parts in total.
- Count the shaded parts: 12 are shaded.
- (a) The fraction is 12⁄20. Divide both parts by 4 to reduce: 3⁄5.
- (b) Convert to a decimal: 3 ÷ 5 = 0.6.
- (c) Multiply by 100 to get a percent: 60%.
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- Add the ratio parts: 2 + 3 + 4 = 9 parts in total.
- Find the value of one part: $450 ÷ 9 = $50.
- Multiply each share by $50: 2 × 50, 3 × 50, 4 × 50.
- Check: 100 + 150 + 200 = 450. ✔
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- Unit rate for Car A: 240 ÷ 3 = 80 km/h.
- Unit rate for Car B: 180 ÷ 2 = 90 km/h.
- Compare: 90 − 80 = 10.
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- When multiplying powers with the same base, add the exponents: 23 × 25 = 28.
- When dividing powers with the same base, subtract the exponents: 28 ÷ 24 = 24.
- Evaluate: 24 = 16.
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- Total earnings: 17.50 × 22 = $385.
- Amount spent: 2⁄5 × 385 = $154.
- Amount left: 385 − 154 = $231.
- Shortcut check: he keeps 3⁄5, and 3⁄5 × 385 = 231. ✔
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- Let the original number be x.
- Increasing by 20% multiplies by 1.2; decreasing by 20% multiplies by 0.8.
- So 1.2 × 0.8 × x = 0.96x, and 0.96x = 96.
- Divide: x = 96 ÷ 0.96 = 100.
- Notice the result is not back to where it started — a 20% rise followed by a 20% fall always loses 4%.
MTH1W Number Sense — common questions
Short answers to the things students ask most about this unit.
What topics are on the Grade 9 number sense unit test?
Integers, fractions, decimals, order of operations (BEDMAS), powers and exponent rules, ratios, rates, proportions and percent problems.
Is MTH1W the same as Grade 9 academic math?
MTH1W replaced both the academic (MPM1D) and applied (MFM1P) Grade 9 courses when Ontario de-streamed Grade 9 math in 2021. Every Grade 9 student now takes the same course.
How do I get better at BEDMAS questions?
Work one operation at a time and write a new line for each step. Most lost marks come from doing two steps mentally at once, especially with negatives and powers.
The classes teach the method behind every one of these.
The solutions above show the steps. The classes teach how to think about the problem in the first place — interactive, and worked through at the student’s own pace. Try 3 complete classes free — no payment required to begin.
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