Summary
Contents
The author focuses especially on weaknesses in numeracy often observed in adults, and in teacher-trainees in particular.
Check-up 14: The Distributive Laws
Check-up 14: The Distributive Laws
There are A pupils in a class. The school charges them each £B to cover the cost of transport for a field trip, plus an additional £C to cover other costs.
- Without a calculator, find the total amount collected if A = 30, B = 25 and C = 6.
- Which of these formulas gives the total amount collected in pounds: A(B + C) or AB + AC?
Discussion and Explanation to Check-up 14
Multiplication is said to be distributive over addition or subtraction. What this means is that if you have to multiply the sum (or difference) of two numbers B and C by a third number ...