Khan Academy Wiki
Signs of products and quotients
Multiply-and-divide-rational-numbers 256
Description
Exercise Name: Signs of products and quotients
Math Missions: 7th grade (U.S.) Math Mission
Types of Problems: 1

The Signs of products and quotients exercise appears under the 7th grade (U.S.) Math Mission. This exercise practices the various rules for products and quotients of positive and negative numbers.

Types of Problems[]

There is one type of problem in this exercise:

  1. Mark whether the expression will be positive or negative: This problem provides a chart with four expressions involving numbers or possibly variables. The student is asked to use the provided information to determine whether the result of the expression will be positive or negative and indicate the answer in the grid.
    Rfmadnn1

    Mark whether the expression will be positive or negative

Strategies[]

Knowledge of arithmetic operations on integers can assist on this problem, specifically knowing the multiplication and division rules.

  1. Some of the problems will have only numbers, and some will have variables.
  2. There can be more than one variable, and the variables can be assigned either positive or negative values, so it is important to read carefully to ensure accuracy.
  3. To increase speed, try counting the number of negatives and the number of negative variable types. If there is an even number of negatives the result will be positive. If there is an odd number, it will be negative.

Real-life Applications[]

  1. Choreographers need to be able to divide the piece they want to perform, into smaller pieces so that everyone will be able to do and give their best, whether they dance or choreograph an orchestra. In the end of the day they need to flow together in harmony and they will use division to accomplish that.
  2. Division is used in group projects so the work is divided and each group member has their own role.
  3. Majority of law issues are arising now are about land division and who lived there first. This requires not just honesty, but also division.
  4. Multiplication is needed and used by mechanics for repairing cars by multiplying when they overhaul the engine, measure the pistons or just to put in a new gearbox or engine.
  5. By learning multiplication and memorizing the times tables, students provide themselves with essential building blocks to do higher learning math, like division, fractions and even algebra.
  6. Multiplication is necessary for a career in the stock market.