1 of 13

Slide Notes

DownloadGo Live

Copy of Algebra Stories

No Description

PRESENTATION OUTLINE

USING VARIABLES

By Rhian Lumsden 7h
Photo by chad.latta

STORY

  • Students are going on a trip to the park for a school assignment.
  • For their assignment, they need to work out how many animal/insect legs there are in the park.
Photo by MSVG

CONT..

  • However, the students don't know how many animals or insects there are, they only know how many legs each animal has and can only guess the number of animals.

VARIABLES

  • To work out how many legs there are in the park, we need to work out some variables that represent the number of each animal.
Photo by Martin LaBar

VARIABLES

  • Let's go with ....
  • N = the total number of legs
  • G = the number of dogs
  • R = the number of birds
  • B = the number of insects
Photo by Etrusia UK

SO WE ALREADY KNOW THAT...

  • Dogs have 4 legs,
  • Birds have 2 legs and
  • Insects have 6 legs.
  • So we just need to find out how many animals there are in the park...

We obviously don't know how many animals there are in the park, so we need to use the variables to represent the number of animals.

Photo by Fred.Thomas

N, g, r and b are our variables, because we can change them,
But 4, 2 and 6 are our constants, because the number of legs each animal has never changes.

Photo by me'nthedogs

Here is the equation :
N = 4g + 2r + 6b

(4g = 4 x g)
(N = 4 x number of dogs + 2 x number of birds + 6 x number of insects)

(SUBSTITUTE) IN ONE SMALL AREA, THERE ARE...

  • 10 dogs
  • 13 birds and
  • 15 insects
  • The equation is now...
  • N = 4 x 10 + 2 x 13 + 6 x 15
Photo by Mark Philpott

WORK OUT!

  • N = 4g + 2r + 6b
  • = 4 x 10 + 2 x 13 + 6 x 15
  • = 40 + 26 + 90
  • = 156
  • There are 156 legs in total!
Photo by Dunechaser

SUBSTITUTE 2

  • There are now 12 dogs,
  • 14 birds and 9 insects

LET'S WORK THIS OUT!

  • N = 4g + 2r + 6b
  • = 4 x 12 + 2 x 14 + 6 x 9
  • = 48 + 28 + 54
  • = 130!
  • The new substitute is 130 legs!
Photo by pix.plz

MORE DECKS BY THIS AUTHOR

Statistics

42 views

Algebra Stories

49 views