Page 168 - NUMINO Challenge_M2
P. 168
2. Masked Numbers
EEExxxeeerrrccciiissseee The number in the hundreds place, , is regrouped 1
from the tens place, so it must be 1. is 9. 111
Looking at the tens place, added to 1 is 11, so
In the ones place, +9=11, so is 2. 1
99
=1 =9 =2 111
EEExxxeeerrrccciiissseee In the ones place, 6+ C =8, so C =2. The tens place 7A6
does not have any regrouped ones, so A +5=11, and
A =6. The hundreds place has 1 regrouped from the +B 5 C
tens, so 1+7+ B = D , and B must be 1, so D =9.
D18
766
+1 5 2
918
Type Study Since + + = , hence there is regrouping, and + =10.
(2-digit number) + (2-digit number) = (3-digit number)
Since the hundreds place in the result is 1, =1 and =9.
- =99-11=88 =8
99
11
+8 8
198
31Answer Key
EEExxxeeerrrccciiissseee The number in the hundreds place, , is regrouped 1
from the tens place, so it must be 1. is 9. 111
Looking at the tens place, added to 1 is 11, so
In the ones place, +9=11, so is 2. 1
99
=1 =9 =2 111
EEExxxeeerrrccciiissseee In the ones place, 6+ C =8, so C =2. The tens place 7A6
does not have any regrouped ones, so A +5=11, and
A =6. The hundreds place has 1 regrouped from the +B 5 C
tens, so 1+7+ B = D , and B must be 1, so D =9.
D18
766
+1 5 2
918
Type Study Since + + = , hence there is regrouping, and + =10.
(2-digit number) + (2-digit number) = (3-digit number)
Since the hundreds place in the result is 1, =1 and =9.
- =99-11=88 =8
99
11
+8 8
198
31Answer Key
