Notes

TUTORIAL

1 :
Mika skip-counted, beginning at 12, until she reached 36. Could she be counting by threes?

Solution :
Explanation

We know that Mika started at 12 and skip-counted until she got to 36. We want to find out if she could have been counting by threes. Try counting like Mika. Start at 12 and count by threes until you say 36 or go past it.


12, 15, 18, 21, 24, 27, 30, 33, 36


Yes, you say 36. Mika could have been counting by threes.

Solution :
Yes



2 :
Abe skip-counted by tens, beginning at 80. Could he have said the number 94?

Solution :
Explanation

We know that Abe started at 80 and skip-counted by tens. We want to find out if he could have said the number 94. Try counting like Abe. Start at 80 and count by tens until you say 94 or go past it.

80, 90, 100

You go past 94 without saying it. Abe could not have said the number 94.

Solution :
No



3 :
Rita skip-counted by threes, beginning at 48. Could she have said the number 76?

Solution :
Explanation

We know that Rita started at 48 and skip-counted by threes. We want to find out if she could have said the number 76. Try counting like Rita. Start at 48 and count by threes until you say 76 or go past it.

48, 51, 54, 57, 60, 63, 66, 69, 72, 75, 78

You go past 76 without saying it. Rita could not have said the number 76.

Solution :
No