Practice Multiple Viewpoints in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

The practice of analyzing the same mathematical object or problem from several different representations, frameworks, or perspectives.

Looking at the same thing from different angles reveals different truths.

Showing a random 20 of 50 problems.

Example 1

medium
Evaluate โˆ‘i=15i\sum_{i=1}^{5} i by direct addition or by the formula n(n+1)2\frac{n(n+1)}{2}. Give the value.

Example 2

easy
Compute 34+14\tfrac{3}{4}+\tfrac{1}{4} as a fraction or as decimals. Give the value.

Example 3

hard
Compute โˆ‘k=1100k\sum_{k=1}^{100}k via the closed-form n(n+1)/2n(n+1)/2 or via pairing 1+100,2+99,โ€ฆ1+100,2+99,\ldots Give the value.

Example 4

easy
The number 12\frac{1}{2} can be viewed as a fraction, a decimal, a probability, and a ratio. Describe each viewpoint and what it emphasises.

Example 5

easy
View โˆฃโˆ’5โˆฃ|{-5}| as a distance from 00 on the number line and also as the algebraic definition maxโก(x,โˆ’x)\max(x,-x). Give the value.

Example 6

medium
The number 0.50.5 as a fraction or as 50%50\% of a whole: a pizza is cut so one person gets 0.50.5. Out of 88 slices, how many do they get?

Example 7

hard
View the equation x3=8x^3=8 as 'find a cube root of 88' (real-number viewpoint) or as a degree-33 polynomial x3โˆ’8=0x^3-8=0 (complex viewpoint). Give all real and complex roots.

Example 8

medium
Compute the distance from (1,2)(1,2) to (4,6)(4,6) via the distance formula or via the Pythagorean theorem with legs 33 and 44. Give the distance.

Example 9

medium
View the Pythagorean theorem a2+b2=c2a^2+b^2=c^2 from three different perspectives: algebraic, geometric, and physical. Give one application for each.

Example 10

easy
Find the area of a right triangle with legs 66 and 88 via 12bh\frac12 bh (give the value).

Example 11

challenge
Compute 1+2+4+8+161+2+4+8+16 as a direct sum or as 25โˆ’12^5-1 (geometric viewpoint). Give the value.

Example 12

easy
Count the dots in a 3ร—43\times4 grid two ways (rows times columns, or columns times rows). Give the count.

Example 13

medium
View 0.9โ€พ0.\overline{9} as the limit of 0.9,0.99,0.999,โ€ฆ0.9,0.99,0.999,\ldots or as the fraction obtained by x=0.9โ€พ,10x=9.9โ€พx=0.\overline{9}, 10x=9.\overline{9}. Give the exact value.

Example 14

easy
View the vector (3,4)(3,4) as Cartesian coordinates or as magnitude-direction. Give its magnitude.

Example 15

easy
Find 12+14\frac{1}{2}+\frac{1}{4} as a fraction or as a decimal. Give the fraction.

Example 16

hard
Prove the inequality a2+b2โ‰ฅ2aba^2+b^2\ge2ab for real a,ba,b by viewing it as (aโˆ’b)2โ‰ฅ0(a-b)^2\ge0 (algebra) or as a fact about non-negative squares (geometry). Give the key identity.

Example 17

medium
Compute (63)\binom{6}{3} using the formula and by listing 3-subsets of {1,2,3,4,5,6}\{1,2,3,4,5,6\}. Give the value.

Example 18

medium
Solve x2โˆ’4=0x^2-4=0 as a difference of squares or by the quadratic formula. Give the solutions.

Example 19

medium
Compute the slope of the line through (2,3)(2,3) and (5,9)(5,9) as rise/run or as tanโก\tan of the angle of inclination. Give the slope.

Example 20

challenge
View the identity โˆ‘k=0n(nk)=2n\sum_{k=0}^{n}\binom{n}{k}=2^n combinatorially (subsets of an nn-set) or via the binomial theorem at x=y=1x=y=1. Give the value at n=10n=10.