The Numbers...

Bethany was showing me how they're learning missing numbers (simple algebra), tonight. They start with a sum like 57 + _ = 84. They have to fill in the missing number.

They've already learnt big number subtraction with borrowing so naturally I figured this is the way to do the sum. What they're actually doing is taking the first number and writing a sequence up to the second number, so...

57 => 60 => 70 => 80 => 84.

They then work out the difference between each number so 3, 10 , 10, 4 then lastly add up the differences. 27.

Quite clever really and very visual.

I added on that she should do them also as upstairs downstairs borrowing so she can check her answers.