Subtract many numbers - video lessons for 1st grade math
In the video below, I first solve two subtraction problems with the help of visuals (strawberries!). Then I explain two different ways to subtract two numbers: subtract them one at a time -- or add the numbers to be subtracted, and subtract the sum.
In the second part (below), we solve subtraction problems such as 9 − 1 − 1 − 1 and 10 − 6 − 3. I show two strategies for these: either subtract the numbers one at a time, or first add all the numbers that are going to be subtracted, then subtract the sum.
Lastly in this second part, we look at some MISSING NUMBER challenges. 😀 Children, pause the video and think about them on your own! Just make a guess, and check if works. 😀
In the last part, we first match visual models to subtraction sentences. Children, pause the video and think!
Then we solve two word problems together. But -- they don't actually have a QUESTION! We need to make up the question for these "word problems". Mathy has a witty question at first! But then he is reminded that math word problems have to do with numbers, not colors. 😀
(It's good to think what CAN be asked... what CAN be solved... with the given info.)
See also
Addition and subtraction facts with 8 (fact families)
Two subtractions from one addition
Math Mammoth Grade 1 curriculum