Adam has 90 marbles at first.
Adam gives away 80 marbles.
How many marbles are there left?
- Which model should we draw?
(1) Model Part-whole
(2) Model Comparison
- Is the total given?
(1) Yes
(2) No
- Who gets the shorter bar?
(1) At first
(2) Adam gives away
- Number of marbles left = _____
(a)
Which model should we draw?
(1) Model Part-whole
(2) Model Comparison
We should draw a (1) Model Part-whole.
(b)
Is the total given?
(1) Yes
(2) No
(1) The total is given.
(c)
Who gets the shorter bar?
(1) At first
(2) Adam gives away
80 marbles is less than 90 marbles. So, (2) 'Adam gives away' gets the shorter bar.
(d)
Number of marbles left
= 90 - 80
= 10
Answer(s): (a) 1; (b) 1; (c) 2; (d) 10