GuruParents's video: Math for Kids - Baseball Batting Average

Math for Kids - Baseball Batting Average by www.guruparents.com If your child likes baseball, the math behind batting average is a great thing to teach them, as it introduces a number of skills. Here’s a reminder of how it works. This is a slightly simplified formula for batting average. So on the top of the fraction it’s the number of hits. And on the bottom it’s the number of plate appearances minus any walks and sacrifice flies. Time for an example - let’s revisit the 2013 World Series and David Ortiz’s amazing performance. Here are big papa’s numbers: He had 25 Plate Appearances. He had 8 walks. And hit 1 sacrifice fly. And he had a colossal 11 hits! So let’s work out the equation. We’ll start at the bottom and tidy it up first. 8 plus 1 = 9. 26 minus 9 = 16. Now it’s fine to use a calculator. 11 divided by 16 = 0.6875. Baseball averages are always given to 3 decimal places, but we have 4, so we have to round it off. The way you do this is to look at the 4th decimal – if it is 4 or under, the third decimal stays at 7. But if it is 5 and over, the 3rd decimal gets rounded up to 8. In this case, because it is 5, we round up, to 8, leaving us with 0.688. Of course, we don’t say batting averages like this. Instead we would say this is six hundred and eighty-eight, or 6 - 88. In effect, we multiply all batting averages by 1000 to make them easier to say. What do I mean? Well, to multiply by 1000, since it has 3 zeroes you move the decimal point 3 places to the right, so .688 becomes 688. Now, let’s compare this to a typical average. Over time, a run of the mill player will average around 270. The great Babe Ruth had a career average of 342. So when you consider that 342 is only a little bit higher than 270, you can see what a totally off the charts effort it was by Big Papa to average 688. But this leads us to our final lesson – sample size. It’s far easier to have a really high – or indeed a really low – average when we’re only talking about a few games. That’s because an extra 1 or 2 hits make such a huge difference. Let’s imagine that Ortiz only had 9 hits, not 11. 9 divided by 16, comes out at an average of 563. Still huge, but a lot less than 688. So, Big Papi’s 2013 World Series was off the charts good – but it is impossible to maintain that average for a whole career – as shown by Ortiz’s career average of 285. So there you have it – that covers off a whole raft of math lessons – order of operations, subtraction, division, fractions, decimals, rounding, multiplication of decimals, some basic statistics and graphs – and yet the whole time, it was just a fun chat about baseball.