Inverse calculations

[muffinflop]

What does this mean? DS has this as a target for next term but he doesn't know what it means. Have googled but confused myself further

The opposite of addition is subtraction.
The opposite of multiplication is division.

3 + 5 = 8
8 - 3 = 5

5 x 9 = 45
45 / 5 = 9

etc

Damn DH was right! Thanks

for level 3, it also includes 'unpicking' word problems and solving them backwards.

That would make sense. He's year 2 and that was his target so I'm guessing he's a 2a?

Children are encouraged to use inverse calculations to check their work, eg
5+2 = 7 so to check 7-2=5
HTH and hasn't made it more confusing.