10th 3770
Andre wants to save $40 to buy a gift for his dad. Andre's neighbor
will pay him weekly to mow the lawn, but Andre always gives a $2
donation to the food bank in weeks when he earns money. Andre
calculates that it will take him 5 weeks to earn the money for his
dad's gift. He draws a tape diagram to represent the situation.
Explain how the parts of the tape diagram represent the story.

10cm represents $10

2cm represents $2

10cm also represents 1week

For every week Andre checks 10cm, deduct 2cm which represents $2 donation for food bank, and remaining 8cm represents $8 left for his Dad's gift.

in 5weeks, which is 50cm, save $8 per week/ per 8cm = $8 × 5 = $40

in 5weeks, which is 50cm, he donate $2 per week/ per 2cm = $2 × 5= $10

a negative exponent is translated as follows:

so, we have