Problem solving

We used place value to solve an equation.

First we start by adding the ones together 4+6=10+7 =17.

Next we add the tens which are 20+20+10=50. Now we add the answers together 17+50=67.

Now we know that she practised for 67 minutes. So now we subtract 67 from 90. 0-7 is impossible to do so we do 10-7=3.

Lastly we do 80-60=20 then we add it together which equals 23 so Leilani needs to practise for another 23 minutes.

I didn't really know what to do so I looked at other peoples and tried getting my own understanding of it.