Matematika

1st grade - basics of subtraction

201648m★ 0
Matematika

A lesson for 1st grade math... learn the CONNECTION between addition and subtraction in an easy way! Just look at the PICTURE. We have a picture with, say, 4 raspberries and 3 blueberries. From that, we can write an addition of course -- but we can ALSO write a subtraction! We just make the one part (4) or the other (3) "go away". In the latter part of this lesson, we also look at "alligator mouth" problems -- or, like Mathy likes to call them, "mammoth mouth" problems. We compare simple expressions, such as 2 + 2 and 5 - 1, and figure which one is greater than the other. Then we solve some simple subtractions. Lastly, I give a challenging word problem concerning Ted's cars, and we solve it by DRAWING.