NAPLAN preparation

There are lots of times you are surprised as a teacher. Today I did some NAPLAN revision of decimal numbers with my year 9 class. It really surprised me how difficult students find the concept of decimal numbers.

Here's something to try with your child.

Draw a number line and place 4.5 at one end and 4.6 at the other.

Place a marker in the middle and ask your child what number would go there.

The answer is 4.55 and many students may get this right, but many would not be 100% sure.

Split the number line again so that it is now in four equal sections. Ask your student to label the new sections.

You may get a wide variety of answers and weird looks.

The answer is 4.5, 4.525, 4.55, 4.575 and 4.6

If your child cannot do this they are not alone. Try again using whole numbers and break it into ten equal sections. Try asking for points between intervals.

Errors like these indicate an issue with both division and place value. It can easily be remedied with some place value exercises (to check if they understand that 4.6 is bigger than 4.59), some estimation exercises (to check if their answers are feasible/reasonable), determining how to find the width of set intervals (using division), learning how to add on intervals and how to find midpoints of intervals.

Time continued...

We were working on applying time calculations today, so I posed a question:

"If [student A] was given detention for 1.4 hours and [student B] was given detention 1 hour 25 minutes detention, who would be in detention the longest?"

Students had a guess and then they reviewed the caterpillar for converting between time units.

We then did a number of calculations with some templates to show how a calculation could be constructed.

Eg

3.4 hours = _______ x ________ mins

= ______________ mins

2 122 131 sec = ________ ÷ _________ ÷ _______ ÷ _______ days

= ____ days

1 hour 20 mins = ________ x _________ + ________ mins

= ______________ mins

After we did that, students were just given a range of questions to solve without the templates.

Eg.

2.8 hours = ___________ minutes

12 hrs 12 minutes = ______ hours

12 hrs 12 minutes = ______ days

Then we revisited our original detention problem and a range of similar problems.

Students then practiced with math-joke type connect-the-answer-with-the-question exercise (the old worksheet with a bad, bad mathematics joke at the bottom to solve). Students were able to solve the majority of problems.

yay!

There's nothing to say that with a stronger group I couldn't have taught the same topic by teaching basic time facts (such as 60sec = 1 minute) and then relied on their application of multiplication and division, but in this case I'm glad I didn't do that, the look on the faces of my students when they realised time calculations made sense (that they had found difficult over a long period) was priceless.