Adam has 90 marbles at first.
Adam gives Bryan some.
Now, Adam has 70 marbles.
How many marbles does Adam give to Bryan?
- 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) Has at first
(2) Has now
- Number of marbles that Adam gives to Bryan = _____
(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) Has at first
(2) Has in the end
70 marbles is less than 90 marbles. So, (2) 'Has in the end' gets the shorter bar.
(d)
Number of marbles that Adam gives Bryan
= 90 - 70
= 20
Answer(s): (a) 1; (b) 1; (c) 2; (d) 20