Estimate the product by rounding the first factor up and the second factor down to the nearest tens:

(a) 45 x 62
(b) 69 x 77
(c) 88 x 17
(d) 55 x 75
(e) 52 x 32
(f) 91 x 24

To estimate the product by rounding the first factor up and the second factor down to the nearest tens, follow these steps for each pair:
(a) 45 x 62 :

Round 45 up to the nearest ten: 50
Round 62 down to the nearest ten: 60

Estimated product: 50 × 60 = 3000
(b) 69 x 77 :

Round 69 up to the nearest ten: 70
Round 77 down to the nearest ten: 70

Estimated product: 70 × 70 = 4900
(c) 88 x 17 :

Round 88 up to the nearest ten: 90
Round 17 down to the nearest ten: 10

Estimated product: 90 × 10 = 900
(d) 55 x 75 :

Round 55 up to the nearest ten: 60
Round 75 down to the nearest ten: 70

Estimated product: 60 × 70 = 4200
(e) 52 x 32 :

Round 52 up to the nearest ten: 60
Round 32 down to the nearest ten: 30

Estimated product: 60 × 30 = 1800
(f) 91 x 24 :

Round 91 up to the nearest ten: 100
Round 24 down to the nearest ten: 20

Estimated product: 100 × 20 = 2000
By rounding the first factor up and the second factor down, we obtain an estimation that is quick and suitable for mental calculation or approximation purposes.

Answered by danjohnbrain | 2025-07-06