____
Sent from my iPhone
Compilation of all things math --- questions obtained via students' consultation, related math sites. * Do also check out my EduTech contributions at go.gov.sg/changcl
Try to follow these guidelines: - 1-mark question to be done within 1minute, 2-mark question within 2 mins, so as to eke out time for 3-mark and above questions - Apply RSVP for questions involving geometry and diagrams/tables/graphs/piecharts - Draw models or do story-boarding when encountering word problems with fraction, ratio, percentage
Most people get this wrong on the first try.
72 ÷ (8 + 4) × 6 − 9
____
Why is it so?
One reason is based on the misconception that multiplication has higher ranking than division.
Another is when people have only a partial understanding of order of operations. While they know that / and x have the same rank, and ought to operate from left to right, they are nevertheless affected by a phenomenon I coined as “the luring of numbers”: given that 12x6=72, and 72/72 will “conveniently” yield 1 for the result of the first 4 numbers (in turn resulting in a wrong final answer of -8) , when it ought to be 36 (where final answer should be 27)