How can a number line be used to model whole number addition and subtraction

2-1=?

If you imagine the number you are subtracting from (2) as a point on a number line, you can add or subtract from that point in whole spaces to end up at you new answer.

At a constant it will take one hour to travel 32 mi.at that speed it will take 1/2 hr to travel the remaining 16 mi.it will take 1+1/2 hr to travel the 48mi @ 32mph.so 1 hr = 60 min& 1/2 hr = 30 min1+1/2 hr = 90 min.there are 60s in each 90 × 60 = 3600 seconds.the real question seriously is he why are they driving so slow? ! lol.

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