Ruka hadi maudhui
The Lumenary
Darasa la 6–8NumberImepangwa

Ratios, rates and proportional reasoning

Ratios, unit rates, percentages and proportional relationships, using tables, double number lines and the constant of proportionality.

math.number.ratios-proportions

Somo la mada hii bado halijaandikwa. Muhtasari ulio hapa chini ni sehemu ya ramani ya mtaala na haujakaguliwa.

Inajengwa juu ya

Masharti ya awali ya lazima 5 (hadi chini kabisa)

Utajifunza

  • Solve ratio and rate problems using tables, double number lines and unit rates.
  • Recognise proportional relationships y = kx in tables, graphs and situations, and identify the constant k.
  • Compute percentages and percentage changes, and explain why a 10% rise followed by a 10% fall does not return to the start.

Fasili

  • A ratio a : b compares two quantities; it is equivalent to ka : kb for every k > 0.
  • A unit rate is the amount of one quantity per one unit of another.
  • Quantities x and y are proportional if y = kx for a fixed constant k.

Nadharia

  • The graph of a proportional relationship is a straight line through the origin.
  • p% of x is (p/100) · x.
  • Successive percentage changes multiply: a 10% increase and then a 10% decrease give an overall factor of 1.1 × 0.9 = 0.99.

Mawazo potofu ya kawaida

  • Using additive reasoning ('3 more') where multiplicative reasoning ('3 times as many') is needed.
  • Thinking every linear relationship is proportional; y = 2x + 1 is not.
  • Adding successive percentage changes.

Inaelekea kwa

Ugunduzi wa hiari

  • Probability When outcomes are equally likely, a probability is the ratio of favourable outcomes to all outcomes.

Njia za kujifunza