Year 10 in England
9th grade number sense
5 9th grade number sense skills, each with a worked example, free practice that checks every answer, and a printable worksheet. Start with a mixed review, or jump to the skill you need.
Mixed review
Ten questions drawn from every skill below.
Simplify surds (radicals)
CCSS HSN.RN.A.2England: GCSE Higher Number
Example
Simplify √80. It can be written as k√5. What is k?
- √80 = √(16 × 5)
- = √16 × √5
- = 4√5
Answer: 4
Error intervals and bounds
CCSS HSN.Q.A.3England: GCSE Foundation NumberEngland: GCSE Higher Number
Example
A measurement is 13.4 kg, correct to 1 decimal place. What is the upper bound?
- 13.4 + 0.05 = 13.45
Answer: 13.45
Builds on: Round decimals
Recurring decimals to fractions
CCSS 8.NS.A.1England: GCSE Higher Number
Example
Write 0.939393… as a fraction in simplest form.
- 100x − x = 93
- 99x = 93
- x = 93/99 = 31/33
Answer: 31/33
Builds on: Fractions as decimals, One-step equations
Multiply and divide surds
CCSS HSN.RN.B.3CCSS 8.EE.A.2England: GCSE Higher Number
Example
Simplify √10 × √5. Give your answer in the form a√b (or a whole number).
- √50 = √(25 × 2)
- = 5√2
Answer: 5√2
Builds on: Simplify surds (radicals)
Add and subtract surds
CCSS HSN.RN.B.3England: GCSE Higher Number
Example
Simplify: 6√5 + 3√5 − 3√5
- (6 + 3 − 3)√5
- = 6√5
Answer: 6√5
Builds on: Simplify surds (radicals)
Leads to: Rationalise denominators like a + √b
Keep exploring
More for 9th grade
Hands-on math tools
- Virtual fraction bars and fraction circles
- Interactive number line
- Virtual base ten blocks
- Multiplication arrays
- Interactive teaching clock
- Virtual money for counting practice
- Interactive coordinate plane
- Algebra balance scale
- Adding fractions with a model
- Virtual algebra tiles
- Alphabetical order game
- Virtual protractor and angle maker
- Area and perimeter builder
- Bar graph maker for kids
- Math by topicFractions, times tables, long division and more
- English and grammarNouns, verbs, commas, spelling and more
- Reading passagesShort stories with read-aloud and questions
- Science by gradePlants, forces, matter, space and more
- Printable worksheetsPrint, or do them on a tablet with a finger or pen
- Free math games3D games where every move is a math question
- Manipulatives and simulationsMath tools plus science sims: cells, atoms, forces, planets
- Fraction calculatorEvery step shown, from mixed numbers to simplest form
- Math 5-a-dayFive fresh warm-up questions every day
- Guides for parentsHow to help with fractions, tables, tests and more
Math, English and science that click.